# class Date

date and datetime class - Tadayoshi Funaba 1998-2011

'date' provides two classes: `Date` and `DateTime`.

## Terms and Definitions¶ ↑

Some terms and definitions are based on ISO 8601 and JIS X 0301.

### Calendar `Date`¶ ↑

The calendar date is a particular day of a calendar year, identified by its ordinal number within a calendar month within that year.

In those classes, this is so-called “civil”.

### Ordinal `Date`¶ ↑

The ordinal date is a particular day of a calendar year identified by its ordinal number within the year.

In those classes, this is so-called “ordinal”.

### Week `Date`¶ ↑

The week date is a date identified by calendar week and day numbers.

The calendar week is a seven day period within a calendar year, starting on a Monday and identified by its ordinal number within the year; the first calendar week of the year is the one that includes the first Thursday of that year. In the Gregorian calendar, this is equivalent to the week which includes January 4.

In those classes, this is so-called “commercial”.

### Julian Day Number¶ ↑

The Julian day number is in elapsed days since noon (Greenwich Mean `Time`) on January 1, 4713 BCE (in the Julian calendar).

In this document, the astronomical Julian day number is the same as the original Julian day number. And the chronological Julian day number is a variation of the Julian day number. Its days begin at midnight on local time.

In this document, when the term “Julian day number” simply appears, it just refers to “chronological Julian day number”, not the original.

In those classes, those are so-called “ajd” and “jd”.

### Modified Julian Day Number¶ ↑

The modified Julian day number is in elapsed days since midnight (Coordinated Universal `Time`) on November 17, 1858 CE (in the Gregorian calendar).

In this document, the astronomical modified Julian day number is the same as the original modified Julian day number. And the chronological modified Julian day number is a variation of the modified Julian day number. Its days begin at midnight on local time.

In this document, when the term “modified Julian day number” simply appears, it just refers to “chronological modified Julian day number”, not the original.

In those classes, those are so-called “amjd” and “mjd”.

## `Date`¶ ↑

A subclass of `Object` that includes the `Comparable` module and easily handles date.

A `Date` object is created with `Date::new`, `Date::jd`, `Date::ordinal`, `Date::commercial`, `Date::parse`, `Date::strptime`, `Date::today`, `Time#to_date`, etc.

    require 'date'

    Date.new(2001,2,3)
     #=> #<Date: 2001-02-03 ...>
    Date.jd(2451944)
     #=> #<Date: 2001-02-03 ...>
    Date.ordinal(2001,34)
     #=> #<Date: 2001-02-03 ...>
    Date.commercial(2001,5,6)
     #=> #<Date: 2001-02-03 ...>
    Date.parse('2001-02-03')
     #=> #<Date: 2001-02-03 ...>
    Date.strptime('03-02-2001', '%d-%m-%Y')
     #=> #<Date: 2001-02-03 ...>
    Time.new(2001,2,3).to_date
     #=> #<Date: 2001-02-03 ...>

All date objects are immutable; hence cannot modify themselves.

The concept of a date object can be represented as a tuple of the day count, the offset and the day of calendar reform.

The day count denotes the absolute position of a temporal dimension. The offset is relative adjustment, which determines decoded local time with the day count. The day of calendar reform denotes the start day of the new style. The old style of the West is the Julian calendar which was adopted by Caesar. The new style is the Gregorian calendar, which is the current civil calendar of many countries.

The day count is virtually the astronomical Julian day number. The offset in this class is usually zero, and cannot be specified directly.

A `Date` object can be created with an optional argument, the day of calendar reform as a Julian day number, which should be 2298874 to 2426355 or negative/positive infinity. The default value is `Date::ITALY` (2299161=1582-10-15). See also sample/cal.rb.

    $ ruby sample/cal.rb -c it 10 1582
        October 1582
     S  M Tu  W Th  F  S
        1  2  3  4 15 16
    17 18 19 20 21 22 23
    24 25 26 27 28 29 30
    31

    $ ruby sample/cal.rb -c gb  9 1752
       September 1752
     S  M Tu  W Th  F  S
           1  2 14 15 16
    17 18 19 20 21 22 23
    24 25 26 27 28 29 30

A `Date` object has various methods. See each reference.

    d = Date.parse('3rd Feb 2001')
                                 #=> #<Date: 2001-02-03 ...>
    d.year                       #=> 2001
    d.mon                        #=> 2
    d.mday                       #=> 3
    d.wday                       #=> 6
    d += 1                       #=> #<Date: 2001-02-04 ...>
    d.strftime('%a %d %b %Y')    #=> "Sun 04 Feb 2001"

### Constants

ABBR_DAYNAMES

  An array of strings of abbreviated day names in `English`. The first is “Sun”.

ABBR_MONTHNAMES

  An array of strings of abbreviated month names in `English`. The first element is nil.

DAYNAMES

  An array of strings of the full names of days of the week in `English`. The first is “Sunday”.

ENGLAND

  The Julian day number of the day of calendar reform for England and her colonies.

GREGORIAN

  The Julian day number of the day of calendar reform for the proleptic Gregorian calendar.

ITALY

  The Julian day number of the day of calendar reform for Italy and some catholic countries.

JULIAN

  The Julian day number of the day of calendar reform for the proleptic Julian calendar.

MONTHNAMES

  An array of strings of full month names in `English`. The first element is nil.

### Public Class Methods

_httpdate(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__httpdate(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__httpdate(str);
    }

_iso8601(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__iso8601(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__iso8601(str);
    }

_jisx0301(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__jisx0301(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__jisx0301(str);
    }

_parse(string[, comp=true], limit: 128) → hash click to toggle source

Parses the given representation of date and time, and returns a hash of parsed elements. This method does not function as a validator.

If the optional second argument is true and the detected year is in the range “00” to “99”, considers the year a 2-digit form and makes it full.

    Date._parse('2001-02-03') #=> {:year=>2001, :mon=>2, :mday=>3}

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__parse(int argc, VALUE *argv, VALUE klass)
    {
        return date_s__parse_internal(argc, argv, klass);
    }

_rfc2822(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__rfc2822(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__rfc2822(str);
    }

_rfc3339(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__rfc3339(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__rfc3339(str);
    }

_rfc822(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__rfc2822(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__rfc2822(str);
    }

_strptime(string[, format='%F']) → hash click to toggle source

Parses the given representation of date and time with the given template, and returns a hash of parsed elements. _strptime does not support specification of flags and width unlike strftime.

    Date._strptime('2001-02-03', '%Y-%m-%d')
                              #=> {:year=>2001, :mon=>2, :mday=>3}

See also strptime(3) and `strftime`.

    static VALUE
    date_s__strptime(int argc, VALUE *argv, VALUE klass)
    {
        return date_s__strptime_internal(argc, argv, klass, "%F");
    }

_xmlschema(string, limit: 128) → hash click to toggle source

Returns a hash of parsed elements.

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s__xmlschema(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, opt;

        rb_scan_args(argc, argv, "1:", &str, &opt);
        check_limit(str, opt);

        return date__xmlschema(str);
    }

civil([year=-4712[, month=1[, mday=1[, start=Date::ITALY]]]]) → date click to toggle source
new([year=-4712[, month=1[, mday=1[, start=Date::ITALY]]]]) → date

Creates a date object denoting the given calendar date.

In this class, BCE years are counted astronomically. Thus, the year before the year 1 is the year zero, and the year preceding the year zero is the year -1. The month and the day of month should be a negative or a positive number (as a relative month/day from the end of year/month when negative). They should not be zero.

The last argument should be a Julian day number which denotes the day of calendar reform. `Date::ITALY` (2299161=1582-10-15), `Date::ENGLAND` (2361222=1752-09-14), `Date::GREGORIAN` (the proleptic Gregorian calendar) and `Date::JULIAN` (the proleptic Julian calendar) can be specified as a day of calendar reform.

    Date.new(2001)            #=> #<Date: 2001-01-01 ...>
    Date.new(2001,2,3)        #=> #<Date: 2001-02-03 ...>
    Date.new(2001,2,-1)       #=> #<Date: 2001-02-28 ...>

See also `::jd`.

    static VALUE
    date_s_civil(int argc, VALUE *argv, VALUE klass)
    {
        return date_initialize(argc, argv, d_lite_s_alloc_simple(klass));
    }

commercial([cwyear=-4712[, cweek=1[, cwday=1[, start=Date::ITALY]]]]) → date click to toggle source

Creates a date object denoting the given week date.

The week and the day of week should be a negative or a positive number (as a relative week/day from the end of year/week when negative). They should not be zero.

    Date.commercial(2001)     #=> #<Date: 2001-01-01 ...>
    Date.commercial(2002)     #=> #<Date: 2001-12-31 ...>
    Date.commercial(2001,5,6) #=> #<Date: 2001-02-03 ...>

See also `::jd` and `::new`.

    static VALUE
    date_s_commercial(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vw, vd, vsg, y, fr, fr2, ret;
        int w, d;
        double sg;

        rb_scan_args(argc, argv, "04", &vy, &vw, &vd, &vsg);

        y = INT2FIX(-4712);
        w = 1;
        d = 1;
        fr2 = INT2FIX(0);
        sg = DEFAULT_SG;

        switch (argc) {
          case 4:
            val2sg(vsg, sg);
          case 3:
            check_numeric(vd, "cwday");
            num2int_with_frac(d, positive_inf);
          case 2:
            check_numeric(vw, "cweek");
            w = NUM2INT(vw);
          case 1:
            check_numeric(vy, "year");
            y = vy;
        }

        {
            VALUE nth;
            int ry, rw, rd, rjd, ns;

            if (!valid_commercial_p(y, w, d, sg,
                                    &nth, &ry,
                                    &rw, &rd, &rjd,
                                    &ns))
                rb_raise(eDateError, "invalid date");

            ret = d_simple_new_internal(klass,
                                        nth, rjd,
                                        sg,
                                        0, 0, 0,
                                        HAVE_JD);
        }
        add_frac();
        return ret;
    }

gregorian_leap?(year) → bool click to toggle source

Returns true if the given year is a leap year of the proleptic Gregorian calendar.

    Date.gregorian_leap?(1900)        #=> false
    Date.gregorian_leap?(2000)        #=> true

    static VALUE
    date_s_gregorian_leap_p(VALUE klass, VALUE y)
    {
        VALUE nth;
        int ry;

        check_numeric(y, "year");
        decode_year(y, -1, &nth, &ry);
        return f_boolcast(c_gregorian_leap_p(ry));
    }

httpdate(string='Mon, 01 Jan -4712 00:00:00 GMT'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some RFC 2616 format.

    Date.httpdate('Sat, 03 Feb 2001 00:00:00 GMT')
                                              #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_httpdate(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);

        switch (argc) {
          case 0:
            str = rb_str_new2("Mon, 01 Jan -4712 00:00:00 GMT");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__httpdate(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

iso8601(string='-4712-01-01'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some typical ISO 8601 formats.

    Date.iso8601('2001-02-03')        #=> #<Date: 2001-02-03 ...>
    Date.iso8601('20010203')          #=> #<Date: 2001-02-03 ...>
    Date.iso8601('2001-W05-6')        #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_iso8601(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
        if (!NIL_P(opt)) argc--;

        switch (argc) {
          case 0:
            str = rb_str_new2("-4712-01-01");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__iso8601(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

jd([jd=0[, start=Date::ITALY]]) → date click to toggle source

Creates a date object denoting the given chronological Julian day number.

    Date.jd(2451944)          #=> #<Date: 2001-02-03 ...>
    Date.jd(2451945)          #=> #<Date: 2001-02-04 ...>
    Date.jd(0)                #=> #<Date: -4712-01-01 ...>

See also `::new`.

    static VALUE
    date_s_jd(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vjd, vsg, jd, fr, fr2, ret;
        double sg;

        rb_scan_args(argc, argv, "02", &vjd, &vsg);

        jd = INT2FIX(0);
        fr2 = INT2FIX(0);
        sg = DEFAULT_SG;

        switch (argc) {
          case 2:
            val2sg(vsg, sg);
          case 1:
            check_numeric(vjd, "jd");
            num2num_with_frac(jd, positive_inf);
        }

        {
            VALUE nth;
            int rjd;

            decode_jd(jd, &nth, &rjd);
            ret = d_simple_new_internal(klass,
                                        nth, rjd,
                                        sg,
                                        0, 0, 0,
                                        HAVE_JD);
        }
        add_frac();
        return ret;
    }

jisx0301(string='-4712-01-01'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some typical JIS X 0301 formats.

    Date.jisx0301('H13.02.03')                #=> #<Date: 2001-02-03 ...>

For no-era year, legacy format, Heisei is assumed.

    Date.jisx0301('13.02.03')                 #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_jisx0301(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
        if (!NIL_P(opt)) argc--;

        switch (argc) {
          case 0:
            str = rb_str_new2("-4712-01-01");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__jisx0301(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

json_create(object) click to toggle source

Deserializes `JSON` string by converting Julian year `y`, month `m`, day `d` and Day of Calendar Reform `sg` to `Date`.

    # File ext/json/lib/json/add/date.rb, line 11
    def self.json_create(object)
      civil(*object.values_at('y', 'm', 'd', 'sg'))
    end

julian_leap?(year) → bool click to toggle source

Returns true if the given year is a leap year of the proleptic Julian calendar.

    Date.julian_leap?(1900)           #=> true
    Date.julian_leap?(1901)           #=> false

    static VALUE
    date_s_julian_leap_p(VALUE klass, VALUE y)
    {
        VALUE nth;
        int ry;

        check_numeric(y, "year");
        decode_year(y, +1, &nth, &ry);
        return f_boolcast(c_julian_leap_p(ry));
    }

leap?(year) → bool click to toggle source

Returns true if the given year is a leap year of the proleptic Gregorian calendar.

    Date.gregorian_leap?(1900)        #=> false
    Date.gregorian_leap?(2000)        #=> true

    static VALUE
    date_s_gregorian_leap_p(VALUE klass, VALUE y)
    {
        VALUE nth;
        int ry;

        check_numeric(y, "year");
        decode_year(y, -1, &nth, &ry);
        return f_boolcast(c_gregorian_leap_p(ry));
    }

new(p1 = v1, p2 = v2, p3 = v3, p4 = v4) click to toggle source

    static VALUE
    date_initialize(int argc, VALUE *argv, VALUE self)
    {
        VALUE vy, vm, vd, vsg, y, fr, fr2, ret;
        int m, d;
        double sg;
        struct SimpleDateData *dat = rb_check_typeddata(self, &d_lite_type);

        if (!simple_dat_p(dat)) {
            rb_raise(rb_eTypeError, "Date expected");
        }

        rb_scan_args(argc, argv, "04", &vy, &vm, &vd, &vsg);

        y = INT2FIX(-4712);
        m = 1;
        d = 1;
        fr2 = INT2FIX(0);
        sg = DEFAULT_SG;

        switch (argc) {
          case 4:
            val2sg(vsg, sg);
          case 3:
            check_numeric(vd, "day");
            num2int_with_frac(d, positive_inf);
          case 2:
            check_numeric(vm, "month");
            m = NUM2INT(vm);
          case 1:
            check_numeric(vy, "year");
            y = vy;
        }

        if (guess_style(y, sg) < 0) {
            VALUE nth;
            int ry, rm, rd;

            if (!valid_gregorian_p(y, m, d,
                                   &nth, &ry,
                                   &rm, &rd))
                rb_raise(eDateError, "invalid date");

            set_to_simple(self, dat, nth, 0, sg, ry, rm, rd, HAVE_CIVIL);
        }
        else {
            VALUE nth;
            int ry, rm, rd, rjd, ns;

            if (!valid_civil_p(y, m, d, sg,
                               &nth, &ry,
                               &rm, &rd, &rjd,
                               &ns))
                rb_raise(eDateError, "invalid date");

            set_to_simple(self, dat, nth, rjd, sg, ry, rm, rd, HAVE_JD | HAVE_CIVIL);
        }
        ret = self;
        add_frac();
        return ret;
    }

new!(p1 = v1, p2 = v2, p3 = v3) click to toggle source

    static VALUE
    date_s_new_bang(int argc, VALUE *argv, VALUE klass)
    {
        VALUE ajd, of, sg, nth, sf;
        int jd, df, rof;
        double rsg;

        rb_scan_args(argc, argv, "03", &ajd, &of, &sg);

        switch (argc) {
          case 0:
            ajd = INT2FIX(0);
          case 1:
            of = INT2FIX(0);
          case 2:
            sg = INT2FIX(DEFAULT_SG);
        }

        old_to_new(ajd, of, sg,
                   &nth, &jd, &df, &sf, &rof, &rsg);

        if (!df && f_zero_p(sf) && !rof)
            return d_simple_new_internal(klass,
                                         nth, jd,
                                         rsg,
                                         0, 0, 0,
                                         HAVE_JD);
        else
            return d_complex_new_internal(klass,
                                          nth, jd,
                                          df, sf,
                                          rof, rsg,
                                          0, 0, 0,
                                          0, 0, 0,
                                          HAVE_JD | HAVE_DF);
    }

nth_kday(p1 = v1, p2 = v2, p3 = v3, p4 = v4, p5 = v5) click to toggle source

    static VALUE
    date_s_nth_kday(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vm, vn, vk, vsg, y, fr, fr2, ret;
        int m, n, k;
        double sg;

        rb_scan_args(argc, argv, "05", &vy, &vm, &vn, &vk, &vsg);

        y = INT2FIX(-4712);
        m = 1;
        n = 1;
        k = 1;
        fr2 = INT2FIX(0);
        sg = DEFAULT_SG;

        switch (argc) {
          case 5:
            val2sg(vsg, sg);
          case 4:
            num2int_with_frac(k, positive_inf);
          case 3:
            n = NUM2INT(vn);
          case 2:
            m = NUM2INT(vm);
          case 1:
            y = vy;
        }

        {
            VALUE nth;
            int ry, rm, rn, rk, rjd, ns;

            if (!valid_nth_kday_p(y, m, n, k, sg,
                                  &nth, &ry,
                                  &rm, &rn, &rk, &rjd,
                                  &ns))
                rb_raise(eDateError, "invalid date");

            ret = d_simple_new_internal(klass,
                                        nth, rjd,
                                        sg,
                                        0, 0, 0,
                                        HAVE_JD);
        }
        add_frac();
        return ret;
    }

ordinal([year=-4712[, yday=1[, start=Date::ITALY]]]) → date click to toggle source

Creates a date object denoting the given ordinal date.

The day of year should be a negative or a positive number (as a relative day from the end of year when negative). It should not be zero.

    Date.ordinal(2001)        #=> #<Date: 2001-01-01 ...>
    Date.ordinal(2001,34)     #=> #<Date: 2001-02-03 ...>
    Date.ordinal(2001,-1)     #=> #<Date: 2001-12-31 ...>

See also `::jd` and `::new`.

    static VALUE
    date_s_ordinal(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vd, vsg, y, fr, fr2, ret;
        int d;
        double sg;

        rb_scan_args(argc, argv, "03", &vy, &vd, &vsg);

        y = INT2FIX(-4712);
        d = 1;
        fr2 = INT2FIX(0);
        sg = DEFAULT_SG;

        switch (argc) {
          case 3:
            val2sg(vsg, sg);
          case 2:
            check_numeric(vd, "yday");
            num2int_with_frac(d, positive_inf);
          case 1:
            check_numeric(vy, "year");
            y = vy;
        }

        {
            VALUE nth;
            int ry, rd, rjd, ns;

            if (!valid_ordinal_p(y, d, sg,
                                 &nth, &ry,
                                 &rd, &rjd,
                                 &ns))
                rb_raise(eDateError, "invalid date");

            ret = d_simple_new_internal(klass,
                                         nth, rjd,
                                         sg,
                                         0, 0, 0,
                                         HAVE_JD);
        }
        add_frac();
        return ret;
    }

parse(string='-4712-01-01'[, comp=true[, start=Date::ITALY]], limit: 128) → date click to toggle source

Parses the given representation of date and time, and creates a date object. This method does not function as a validator.

If the optional second argument is true and the detected year is in the range “00” to “99”, considers the year a 2-digit form and makes it full.

    Date.parse('2001-02-03')          #=> #<Date: 2001-02-03 ...>
    Date.parse('20010203')            #=> #<Date: 2001-02-03 ...>
    Date.parse('3rd Feb 2001')        #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_parse(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, comp, sg, opt;

        rb_scan_args(argc, argv, "03:", &str, &comp, &sg, &opt);
        if (!NIL_P(opt)) argc--;

        switch (argc) {
          case 0:
            str = rb_str_new2("-4712-01-01");
          case 1:
            comp = Qtrue;
          case 2:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 2;
            VALUE argv2[3];
            argv2[0] = str;
            argv2[1] = comp;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__parse(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

rfc2822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some typical RFC 2822 formats.

    Date.rfc2822('Sat, 3 Feb 2001 00:00:00 +0000')
                                              #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_rfc2822(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);

        switch (argc) {
          case 0:
            str = rb_str_new2("Mon, 1 Jan -4712 00:00:00 +0000");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__rfc2822(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

rfc3339(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some typical RFC 3339 formats.

    Date.rfc3339('2001-02-03T04:05:06+07:00') #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_rfc3339(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
        if (!NIL_P(opt)) argc--;

        switch (argc) {
          case 0:
            str = rb_str_new2("-4712-01-01T00:00:00+00:00");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__rfc3339(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

rfc822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some typical RFC 2822 formats.

    Date.rfc2822('Sat, 3 Feb 2001 00:00:00 +0000')
                                              #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_rfc2822(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);

        switch (argc) {
          case 0:
            str = rb_str_new2("Mon, 1 Jan -4712 00:00:00 +0000");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__rfc2822(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

strptime([string='-4712-01-01'[, format='%F'[, start=Date::ITALY]]]) → date click to toggle source

Parses the given representation of date and time with the given template, and creates a date object. strptime does not support specification of flags and width unlike strftime.

    Date.strptime('2001-02-03', '%Y-%m-%d')   #=> #<Date: 2001-02-03 ...>
    Date.strptime('03-02-2001', '%d-%m-%Y')   #=> #<Date: 2001-02-03 ...>
    Date.strptime('2001-034', '%Y-%j')        #=> #<Date: 2001-02-03 ...>
    Date.strptime('2001-W05-6', '%G-W%V-%u')  #=> #<Date: 2001-02-03 ...>
    Date.strptime('2001 04 6', '%Y %U %w')    #=> #<Date: 2001-02-03 ...>
    Date.strptime('2001 05 6', '%Y %W %u')    #=> #<Date: 2001-02-03 ...>
    Date.strptime('sat3feb01', '%a%d%b%y')    #=> #<Date: 2001-02-03 ...>

See also strptime(3) and `strftime`.

    static VALUE
    date_s_strptime(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, fmt, sg;

        rb_scan_args(argc, argv, "03", &str, &fmt, &sg);

        switch (argc) {
          case 0:
            str = rb_str_new2("-4712-01-01");
          case 1:
            fmt = rb_str_new2("%F");
          case 2:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            VALUE argv2[2], hash;

            argv2[0] = str;
            argv2[1] = fmt;
            hash = date_s__strptime(2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

test_all() click to toggle source

    static VALUE
    date_s_test_all(VALUE klass)
    {
        if (date_s_test_civil(klass) == Qfalse)
            return Qfalse;
        if (date_s_test_ordinal(klass) == Qfalse)
            return Qfalse;
        if (date_s_test_commercial(klass) == Qfalse)
            return Qfalse;
        if (date_s_test_weeknum(klass) == Qfalse)
            return Qfalse;
        if (date_s_test_nth_kday(klass) == Qfalse)
            return Qfalse;
        if (date_s_test_unit_conv(klass) == Qfalse)
            return Qfalse;
        return Qtrue;
    }

test_civil() click to toggle source

    static VALUE
    date_s_test_civil(VALUE klass)
    {
        if (!test_civil(MIN_JD, MIN_JD + 366, GREGORIAN))
            return Qfalse;
        if (!test_civil(2305814, 2598007, GREGORIAN))
            return Qfalse;
        if (!test_civil(MAX_JD - 366, MAX_JD, GREGORIAN))
            return Qfalse;

        if (!test_civil(MIN_JD, MIN_JD + 366, ITALY))
            return Qfalse;
        if (!test_civil(2305814, 2598007, ITALY))
            return Qfalse;
        if (!test_civil(MAX_JD - 366, MAX_JD, ITALY))
            return Qfalse;

        return Qtrue;
    }

test_commercial() click to toggle source

    static VALUE
    date_s_test_commercial(VALUE klass)
    {
        if (!test_commercial(MIN_JD, MIN_JD + 366, GREGORIAN))
            return Qfalse;
        if (!test_commercial(2305814, 2598007, GREGORIAN))
            return Qfalse;
        if (!test_commercial(MAX_JD - 366, MAX_JD, GREGORIAN))
            return Qfalse;

        if (!test_commercial(MIN_JD, MIN_JD + 366, ITALY))
            return Qfalse;
        if (!test_commercial(2305814, 2598007, ITALY))
            return Qfalse;
        if (!test_commercial(MAX_JD - 366, MAX_JD, ITALY))
            return Qfalse;

        return Qtrue;
    }

test_nth_kday() click to toggle source

    static VALUE
    date_s_test_nth_kday(VALUE klass)
    {
        if (!test_nth_kday(MIN_JD, MIN_JD + 366, GREGORIAN))
            return Qfalse;
        if (!test_nth_kday(2305814, 2598007, GREGORIAN))
            return Qfalse;
        if (!test_nth_kday(MAX_JD - 366, MAX_JD, GREGORIAN))
            return Qfalse;

        if (!test_nth_kday(MIN_JD, MIN_JD + 366, ITALY))
            return Qfalse;
        if (!test_nth_kday(2305814, 2598007, ITALY))
            return Qfalse;
        if (!test_nth_kday(MAX_JD - 366, MAX_JD, ITALY))
            return Qfalse;

        return Qtrue;
    }

test_ordinal() click to toggle source

    static VALUE
    date_s_test_ordinal(VALUE klass)
    {
        if (!test_ordinal(MIN_JD, MIN_JD + 366, GREGORIAN))
            return Qfalse;
        if (!test_ordinal(2305814, 2598007, GREGORIAN))
            return Qfalse;
        if (!test_ordinal(MAX_JD - 366, MAX_JD, GREGORIAN))
            return Qfalse;

        if (!test_ordinal(MIN_JD, MIN_JD + 366, ITALY))
            return Qfalse;
        if (!test_ordinal(2305814, 2598007, ITALY))
            return Qfalse;
        if (!test_ordinal(MAX_JD - 366, MAX_JD, ITALY))
            return Qfalse;

        return Qtrue;
    }

test_unit_conv() click to toggle source

    static VALUE
    date_s_test_unit_conv(VALUE klass)
    {
        if (!test_unit_v2v_iter(sec_to_day, day_to_sec))
            return Qfalse;
        if (!test_unit_v2v_iter(ms_to_sec, sec_to_ms))
            return Qfalse;
        if (!test_unit_v2v_iter(ns_to_day, day_to_ns))
            return Qfalse;
        if (!test_unit_v2v_iter(ns_to_sec, sec_to_ns))
            return Qfalse;
        return Qtrue;
    }

test_weeknum() click to toggle source

    static VALUE
    date_s_test_weeknum(VALUE klass)
    {
        int f;

        for (f = 0; f <= 1; f++) {
            if (!test_weeknum(MIN_JD, MIN_JD + 366, f, GREGORIAN))
                return Qfalse;
            if (!test_weeknum(2305814, 2598007, f, GREGORIAN))
                return Qfalse;
            if (!test_weeknum(MAX_JD - 366, MAX_JD, f, GREGORIAN))
                return Qfalse;

            if (!test_weeknum(MIN_JD, MIN_JD + 366, f, ITALY))
                return Qfalse;
            if (!test_weeknum(2305814, 2598007, f, ITALY))
                return Qfalse;
            if (!test_weeknum(MAX_JD - 366, MAX_JD, f, ITALY))
                return Qfalse;
        }

        return Qtrue;
    }

today([start=Date::ITALY]) → date click to toggle source

Creates a date object denoting the present day.

    Date.today   #=> #<Date: 2011-06-11 ...>

    static VALUE
    date_s_today(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vsg, nth, ret;
        double sg;
        time_t t;
        struct tm tm;
        int y, ry, m, d;

        rb_scan_args(argc, argv, "01", &vsg);

        if (argc < 1)
            sg = DEFAULT_SG;
        else
            val2sg(vsg, sg);

        if (time(&t) == -1)
            rb_sys_fail("time");
        tzset();
        if (!localtime_r(&t, &tm))
            rb_sys_fail("localtime");

        y = tm.tm_year + 1900;
        m = tm.tm_mon + 1;
        d = tm.tm_mday;

        decode_year(INT2FIX(y), -1, &nth, &ry);

        ret = d_simple_new_internal(klass,
                                    nth, 0,
                                    GREGORIAN,
                                    ry, m, d,
                                    HAVE_CIVIL);
        {
            get_d1(ret);
            set_sg(dat, sg);
        }
        return ret;
    }

valid_civil?(year, month, mday[, start=Date::ITALY]) → bool click to toggle source

Returns true if the given calendar date is valid, and false if not. Valid in this context is whether the arguments passed to this method would be accepted by `::new`.

    Date.valid_date?(2001,2,3)        #=> true
    Date.valid_date?(2001,2,29)       #=> false
    Date.valid_date?(2001,2,-1)       #=> true

See also `::jd` and `::civil`.

    static VALUE
    date_s_valid_civil_p(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vm, vd, vsg;
        VALUE argv2[4];

        rb_scan_args(argc, argv, "31", &vy, &vm, &vd, &vsg);

        RETURN_FALSE_UNLESS_NUMERIC(vy);
        RETURN_FALSE_UNLESS_NUMERIC(vm);
        RETURN_FALSE_UNLESS_NUMERIC(vd);
        argv2[0] = vy;
        argv2[1] = vm;
        argv2[2] = vd;
        if (argc < 4)
            argv2[3] = INT2FIX(DEFAULT_SG);
        else
            argv2[3] = vsg;

        if (NIL_P(valid_civil_sub(4, argv2, klass, 0)))
            return Qfalse;
        return Qtrue;
    }

valid_commercial?(cwyear, cweek, cwday[, start=Date::ITALY]) → bool click to toggle source

Returns true if the given week date is valid, and false if not.

    Date.valid_commercial?(2001,5,6)  #=> true
    Date.valid_commercial?(2001,5,8)  #=> false

See also `::jd` and `::commercial`.

    static VALUE
    date_s_valid_commercial_p(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vw, vd, vsg;
        VALUE argv2[4];

        rb_scan_args(argc, argv, "31", &vy, &vw, &vd, &vsg);

        RETURN_FALSE_UNLESS_NUMERIC(vy);
        RETURN_FALSE_UNLESS_NUMERIC(vw);
        RETURN_FALSE_UNLESS_NUMERIC(vd);
        argv2[0] = vy;
        argv2[1] = vw;
        argv2[2] = vd;
        if (argc < 4)
            argv2[3] = INT2FIX(DEFAULT_SG);
        else
            argv2[3] = vsg;

        if (NIL_P(valid_commercial_sub(4, argv2, klass, 0)))
            return Qfalse;
        return Qtrue;
    }

valid_date?(year, month, mday[, start=Date::ITALY]) → bool click to toggle source

Returns true if the given calendar date is valid, and false if not. Valid in this context is whether the arguments passed to this method would be accepted by `::new`.

    Date.valid_date?(2001,2,3)        #=> true
    Date.valid_date?(2001,2,29)       #=> false
    Date.valid_date?(2001,2,-1)       #=> true

See also `::jd` and `::civil`.

    static VALUE
    date_s_valid_civil_p(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vm, vd, vsg;
        VALUE argv2[4];

        rb_scan_args(argc, argv, "31", &vy, &vm, &vd, &vsg);

        RETURN_FALSE_UNLESS_NUMERIC(vy);
        RETURN_FALSE_UNLESS_NUMERIC(vm);
        RETURN_FALSE_UNLESS_NUMERIC(vd);
        argv2[0] = vy;
        argv2[1] = vm;
        argv2[2] = vd;
        if (argc < 4)
            argv2[3] = INT2FIX(DEFAULT_SG);
        else
            argv2[3] = vsg;

        if (NIL_P(valid_civil_sub(4, argv2, klass, 0)))
            return Qfalse;
        return Qtrue;
    }

valid_jd?(jd[, start=Date::ITALY]) → bool click to toggle source

Just returns true. It's nonsense, but is for symmetry.

    Date.valid_jd?(2451944)           #=> true

See also `::jd`.

    static VALUE
    date_s_valid_jd_p(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vjd, vsg;
        VALUE argv2[2];

        rb_scan_args(argc, argv, "11", &vjd, &vsg);

        RETURN_FALSE_UNLESS_NUMERIC(vjd);
        argv2[0] = vjd;
        if (argc < 2)
            argv2[1] = INT2FIX(DEFAULT_SG);
        else
            argv2[1] = vsg;

        if (NIL_P(valid_jd_sub(2, argv2, klass, 0)))
            return Qfalse;
        return Qtrue;
    }

valid_ordinal?(year, yday[, start=Date::ITALY]) → bool click to toggle source

Returns true if the given ordinal date is valid, and false if not.

    Date.valid_ordinal?(2001,34)      #=> true
    Date.valid_ordinal?(2001,366)     #=> false

See also `::jd` and `::ordinal`.

    static VALUE
    date_s_valid_ordinal_p(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vd, vsg;
        VALUE argv2[3];

        rb_scan_args(argc, argv, "21", &vy, &vd, &vsg);

        RETURN_FALSE_UNLESS_NUMERIC(vy);
        RETURN_FALSE_UNLESS_NUMERIC(vd);
        argv2[0] = vy;
        argv2[1] = vd;
        if (argc < 3)
            argv2[2] = INT2FIX(DEFAULT_SG);
        else
            argv2[2] = vsg;

        if (NIL_P(valid_ordinal_sub(3, argv2, klass, 0)))
            return Qfalse;
        return Qtrue;
    }

weeknum(p1 = v1, p2 = v2, p3 = v3, p4 = v4, p5 = v5) click to toggle source

    static VALUE
    date_s_weeknum(int argc, VALUE *argv, VALUE klass)
    {
        VALUE vy, vw, vd, vf, vsg, y, fr, fr2, ret;
        int w, d, f;
        double sg;

        rb_scan_args(argc, argv, "05", &vy, &vw, &vd, &vf, &vsg);

        y = INT2FIX(-4712);
        w = 0;
        d = 1;
        f = 0;
        fr2 = INT2FIX(0);
        sg = DEFAULT_SG;

        switch (argc) {
          case 5:
            val2sg(vsg, sg);
          case 4:
            f = NUM2INT(vf);
          case 3:
            num2int_with_frac(d, positive_inf);
          case 2:
            w = NUM2INT(vw);
          case 1:
            y = vy;
        }

        {
            VALUE nth;
            int ry, rw, rd, rjd, ns;

            if (!valid_weeknum_p(y, w, d, f, sg,
                                 &nth, &ry,
                                 &rw, &rd, &rjd,
                                 &ns))
                rb_raise(eDateError, "invalid date");

            ret = d_simple_new_internal(klass,
                                        nth, rjd,
                                        sg,
                                        0, 0, 0,
                                        HAVE_JD);
        }
        add_frac();
        return ret;
    }

xmlschema(string='-4712-01-01'[, start=Date::ITALY], limit: 128) → date click to toggle source

Creates a new `Date` object by parsing from a string according to some typical `XML` Schema formats.

    Date.xmlschema('2001-02-03')      #=> #<Date: 2001-02-03 ...>

Raise an `ArgumentError` when the string length is longer than limit. You can stop this check by passing `limit: nil`, but note that it may take a long time to parse.

    static VALUE
    date_s_xmlschema(int argc, VALUE *argv, VALUE klass)
    {
        VALUE str, sg, opt;

        rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
        if (!NIL_P(opt)) argc--;

        switch (argc) {
          case 0:
            str = rb_str_new2("-4712-01-01");
          case 1:
            sg = INT2FIX(DEFAULT_SG);
        }

        {
            int argc2 = 1;
            VALUE argv2[2];
            argv2[0] = str;
            if (!NIL_P(opt)) argv2[argc2++] = opt;
            VALUE hash = date_s__xmlschema(argc2, argv2, klass);
            return d_new_by_frags(klass, hash, sg);
        }
    }

### Public Instance Methods

d + other → date click to toggle source

Returns a date object pointing `other` days after self. The other should be a numeric value. If the other is a fractional number, assumes its precision is at most nanosecond.

    Date.new(2001,2,3) + 1    #=> #<Date: 2001-02-04 ...>
    DateTime.new(2001,2,3) + Rational(1,2)
                              #=> #<DateTime: 2001-02-03T12:00:00+00:00 ...>
    DateTime.new(2001,2,3) + Rational(-1,2)
                              #=> #<DateTime: 2001-02-02T12:00:00+00:00 ...>
    DateTime.jd(0,12) + DateTime.new(2001,2,3).ajd
                              #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...>

    static VALUE
    d_lite_plus(VALUE self, VALUE other)
    {
        int try_rational = 1;
        get_d1(self);

      again:
        switch (TYPE(other)) {
          case T_FIXNUM:
            {
                VALUE nth;
                long t;
                int jd;

                nth = m_nth(dat);
                t = FIX2LONG(other);
                if (DIV(t, CM_PERIOD)) {
                    nth = f_add(nth, INT2FIX(DIV(t, CM_PERIOD)));
                    t = MOD(t, CM_PERIOD);
                }

                if (!t)
                    jd = m_jd(dat);
                else {
                    jd = m_jd(dat) + (int)t;
                    canonicalize_jd(nth, jd);
                }

                if (simple_dat_p(dat))
                    return d_simple_new_internal(rb_obj_class(self),
                                                 nth, jd,
                                                 dat->s.sg,
                                                 0, 0, 0,
                                                 (dat->s.flags | HAVE_JD) &
                                                 ~HAVE_CIVIL);
                else
                    return d_complex_new_internal(rb_obj_class(self),
                                                  nth, jd,
                                                  dat->c.df, dat->c.sf,
                                                  dat->c.of, dat->c.sg,
                                                  0, 0, 0,
    #ifndef USE_PACK
                                                  dat->c.hour,
                                                  dat->c.min,
                                                  dat->c.sec,
    #else
                                                  EX_HOUR(dat->c.pc),
                                                  EX_MIN(dat->c.pc),
                                                  EX_SEC(dat->c.pc),
    #endif
                                                  (dat->c.flags | HAVE_JD) &
                                                  ~HAVE_CIVIL);
            }
            break;
          case T_BIGNUM:
            {
                VALUE nth;
                int jd, s;

                if (f_positive_p(other))
                    s = +1;
                else {
                    s = -1;
                    other = f_negate(other);
                }

                nth = f_idiv(other, INT2FIX(CM_PERIOD));
                jd = FIX2INT(f_mod(other, INT2FIX(CM_PERIOD)));

                if (s < 0) {
                    nth = f_negate(nth);
                    jd = -jd;
                }

                if (!jd)
                    jd = m_jd(dat);
                else {
                    jd = m_jd(dat) + jd;
                    canonicalize_jd(nth, jd);
                }

                if (f_zero_p(nth))
                    nth = m_nth(dat);
                else
                    nth = f_add(m_nth(dat), nth);

                if (simple_dat_p(dat))
                    return d_simple_new_internal(rb_obj_class(self),
                                                 nth, jd,
                                                 dat->s.sg,
                                                 0, 0, 0,
                                                 (dat->s.flags | HAVE_JD) &
                                                 ~HAVE_CIVIL);
                else
                    return d_complex_new_internal(rb_obj_class(self),
                                                  nth, jd,
                                                  dat->c.df, dat->c.sf,
                                                  dat->c.of, dat->c.sg,
                                                  0, 0, 0,
    #ifndef USE_PACK
                                                  dat->c.hour,
                                                  dat->c.min,
                                                  dat->c.sec,
    #else
                                                  EX_HOUR(dat->c.pc),
                                                  EX_MIN(dat->c.pc),
                                                  EX_SEC(dat->c.pc),
    #endif
                                                  (dat->c.flags | HAVE_JD) &
                                                  ~HAVE_CIVIL);
            }
            break;
          case T_FLOAT:
            {
                double jd, o, tmp;
                int s, df;
                VALUE nth, sf;

                o = RFLOAT_VALUE(other);

                if (o > 0)
                    s = +1;
                else {
                    s = -1;
                    o = -o;
                }

                o = modf(o, &tmp);

                if (!floor(tmp / CM_PERIOD)) {
                    nth = INT2FIX(0);
                    jd = (int)tmp;
                }
                else {
                    double i, f;

                    f = modf(tmp / CM_PERIOD, &i);
                    nth = f_floor(DBL2NUM(i));
                    jd = (int)(f * CM_PERIOD);
                }

                o *= DAY_IN_SECONDS;
                o = modf(o, &tmp);
                df = (int)tmp;
                o *= SECOND_IN_NANOSECONDS;
                sf = INT2FIX((int)round(o));

                if (s < 0) {
                    jd = -jd;
                    df = -df;
                    sf = f_negate(sf);
                }

                if (f_zero_p(sf))
                    sf = m_sf(dat);
                else {
                    sf = f_add(m_sf(dat), sf);
                    if (f_lt_p(sf, INT2FIX(0))) {
                        df -= 1;
                        sf = f_add(sf, INT2FIX(SECOND_IN_NANOSECONDS));
                    }
                    else if (f_ge_p(sf, INT2FIX(SECOND_IN_NANOSECONDS))) {
                        df += 1;
                        sf = f_sub(sf, INT2FIX(SECOND_IN_NANOSECONDS));
                    }
                }

                if (!df)
                    df = m_df(dat);
                else {
                    df = m_df(dat) + df;
                    if (df < 0) {
                        jd -= 1;
                        df += DAY_IN_SECONDS;
                    }
                    else if (df >= DAY_IN_SECONDS) {
                        jd += 1;
                        df -= DAY_IN_SECONDS;
                    }
                }

                if (!jd)
                    jd = m_jd(dat);
                else {
                    jd = m_jd(dat) + jd;
                    canonicalize_jd(nth, jd);
                }

                if (f_zero_p(nth))
                    nth = m_nth(dat);
                else
                    nth = f_add(m_nth(dat), nth);

                if (!df && f_zero_p(sf) && !m_of(dat))
                    return d_simple_new_internal(rb_obj_class(self),
                                                 nth, (int)jd,
                                                 m_sg(dat),
                                                 0, 0, 0,
                                                 (dat->s.flags | HAVE_JD) &
                                                 ~(HAVE_CIVIL | HAVE_TIME |
                                                   COMPLEX_DAT));
                else
                    return d_complex_new_internal(rb_obj_class(self),
                                                  nth, (int)jd,
                                                  df, sf,
                                                  m_of(dat), m_sg(dat),
                                                  0, 0, 0,
                                                  0, 0, 0,
                                                  (dat->c.flags |
                                                   HAVE_JD | HAVE_DF) &
                                                  ~(HAVE_CIVIL | HAVE_TIME));
            }
            break;
          default:
            expect_numeric(other);
            other = f_to_r(other);
            if (!k_rational_p(other)) {
                if (!try_rational) Check_Type(other, T_RATIONAL);
                try_rational = 0;
                goto again;
            }
            /* fall through */
          case T_RATIONAL:
            {
                VALUE nth, sf, t;
                int jd, df, s;

                if (wholenum_p(other)) {
                    other = rb_rational_num(other);
                    goto again;
                }

                if (f_positive_p(other))
                    s = +1;
                else {
                    s = -1;
                    other = f_negate(other);
                }

                nth = f_idiv(other, INT2FIX(CM_PERIOD));
                t = f_mod(other, INT2FIX(CM_PERIOD));

                jd = FIX2INT(f_idiv(t, INT2FIX(1)));
                t = f_mod(t, INT2FIX(1));

                t = f_mul(t, INT2FIX(DAY_IN_SECONDS));
                df = FIX2INT(f_idiv(t, INT2FIX(1)));
                t = f_mod(t, INT2FIX(1));

                sf = f_mul(t, INT2FIX(SECOND_IN_NANOSECONDS));

                if (s < 0) {
                    nth = f_negate(nth);
                    jd = -jd;
                    df = -df;
                    sf = f_negate(sf);
                }

                if (f_zero_p(sf))
                    sf = m_sf(dat);
                else {
                    sf = f_add(m_sf(dat), sf);
                    if (f_lt_p(sf, INT2FIX(0))) {
                        df -= 1;
                        sf = f_add(sf, INT2FIX(SECOND_IN_NANOSECONDS));
                    }
                    else if (f_ge_p(sf, INT2FIX(SECOND_IN_NANOSECONDS))) {
                        df += 1;
                        sf = f_sub(sf, INT2FIX(SECOND_IN_NANOSECONDS));
                    }
                }

                if (!df)
                    df = m_df(dat);
                else {
                    df = m_df(dat) + df;
                    if (df < 0) {
                        jd -= 1;
                        df += DAY_IN_SECONDS;
                    }
                    else if (df >= DAY_IN_SECONDS) {
                        jd += 1;
                        df -= DAY_IN_SECONDS;
                    }
                }

                if (!jd)
                    jd = m_jd(dat);
                else {
                    jd = m_jd(dat) + jd;
                    canonicalize_jd(nth, jd);
                }

                if (f_zero_p(nth))
                    nth = m_nth(dat);
                else
                    nth = f_add(m_nth(dat), nth);

                if (!df && f_zero_p(sf) && !m_of(dat))
                    return d_simple_new_internal(rb_obj_class(self),
                                                 nth, jd,
                                                 m_sg(dat),
                                                 0, 0, 0,
                                                 (dat->s.flags | HAVE_JD) &
                                                 ~(HAVE_CIVIL | HAVE_TIME |
                                                   COMPLEX_DAT));
                else
                    return d_complex_new_internal(rb_obj_class(self),
                                                  nth, jd,
                                                  df, sf,
                                                  m_of(dat), m_sg(dat),
                                                  0, 0, 0,
                                                  0, 0, 0,
                                                  (dat->c.flags |
                                                   HAVE_JD | HAVE_DF) &
                                                  ~(HAVE_CIVIL | HAVE_TIME));
            }
            break;
        }
    }

d - other → date or rational click to toggle source

Returns the difference between the two dates if the other is a date object. If the other is a numeric value, returns a date object pointing `other` days before self. If the other is a fractional number, assumes its precision is at most nanosecond.

    Date.new(2001,2,3) - 1   #=> #<Date: 2001-02-02 ...>
    DateTime.new(2001,2,3) - Rational(1,2)
                             #=> #<DateTime: 2001-02-02T12:00:00+00:00 ...>
    Date.new(2001,2,3) - Date.new(2001)
                             #=> (33/1)
    DateTime.new(2001,2,3) - DateTime.new(2001,2,2,12)
                             #=> (1/2)

    static VALUE
    d_lite_minus(VALUE self, VALUE other)
    {
        if (k_date_p(other))
            return minus_dd(self, other);

        switch (TYPE(other)) {
          case T_FIXNUM:
            return d_lite_plus(self, LONG2NUM(-FIX2LONG(other)));
          case T_FLOAT:
            return d_lite_plus(self, DBL2NUM(-RFLOAT_VALUE(other)));
          default:
            expect_numeric(other);
            /* fall through */
          case T_BIGNUM:
          case T_RATIONAL:
            return d_lite_plus(self, f_negate(other));
        }
    }

d << n → date click to toggle source

Returns a date object pointing `n` months before self. The argument `n` should be a numeric value.

    Date.new(2001,2,3)  <<  1   #=> #<Date: 2001-01-03 ...>
    Date.new(2001,2,3)  << -2   #=> #<Date: 2001-04-03 ...>

When the same day does not exist for the corresponding month, the last day of the month is used instead:

    Date.new(2001,3,28) << 1   #=> #<Date: 2001-02-28 ...>
    Date.new(2001,3,31) << 1   #=> #<Date: 2001-02-28 ...>

This also results in the following, possibly unexpected, behavior:

    Date.new(2001,3,31) << 2         #=> #<Date: 2001-01-31 ...>
    Date.new(2001,3,31) << 1 << 1    #=> #<Date: 2001-01-28 ...>

    Date.new(2001,3,31) << 1 << -1   #=> #<Date: 2001-03-28 ...>

    static VALUE
    d_lite_lshift(VALUE self, VALUE other)
    {
        expect_numeric(other);
        return d_lite_rshift(self, f_negate(other));
    }

d <=> other → -1, 0, +1 or nil click to toggle source

Compares the two dates and returns -1, zero, 1 or nil. The other should be a date object or a numeric value as an astronomical Julian day number.

    Date.new(2001,2,3) <=> Date.new(2001,2,4)   #=> -1
    Date.new(2001,2,3) <=> Date.new(2001,2,3)   #=> 0
    Date.new(2001,2,3) <=> Date.new(2001,2,2)   #=> 1
    Date.new(2001,2,3) <=> Object.new           #=> nil
    Date.new(2001,2,3) <=> Rational(4903887,2)  #=> 0

See also `Comparable`.

    static VALUE
    d_lite_cmp(VALUE self, VALUE other)
    {
        if (!k_date_p(other))
            return cmp_gen(self, other);

        {
            get_d2(self, other);

            if (!(simple_dat_p(adat) && simple_dat_p(bdat) &&
                  m_gregorian_p(adat) == m_gregorian_p(bdat)))
                return cmp_dd(self, other);

            {
                VALUE a_nth, b_nth;
                int a_jd, b_jd;

                m_canonicalize_jd(self, adat);
                m_canonicalize_jd(other, bdat);
                a_nth = m_nth(adat);
                b_nth = m_nth(bdat);
                if (f_eqeq_p(a_nth, b_nth)) {
                    a_jd = m_jd(adat);
                    b_jd = m_jd(bdat);
                    if (a_jd == b_jd) {
                        return INT2FIX(0);
                    }
                    else if (a_jd < b_jd) {
                        return INT2FIX(-1);
                    }
                    else {
                        return INT2FIX(1);
                    }
                }
                else if (f_lt_p(a_nth, b_nth)) {
                    return INT2FIX(-1);
                }
                else {
                    return INT2FIX(1);
                }
            }
        }
    }

d === other → bool click to toggle source

Returns true if they are the same day.

    Date.new(2001,2,3) === Date.new(2001,2,3)
                                      #=> true
    Date.new(2001,2,3) === Date.new(2001,2,4)
                                      #=> false
    DateTime.new(2001,2,3) === DateTime.new(2001,2,3,12)
                                      #=> true
    DateTime.new(2001,2,3) === DateTime.new(2001,2,3,0,0,0,'+24:00')
                                      #=> true
    DateTime.new(2001,2,3) === DateTime.new(2001,2,4,0,0,0,'+24:00')
                                      #=> false

    static VALUE
    d_lite_equal(VALUE self, VALUE other)
    {
        if (!k_date_p(other))
            return equal_gen(self, other);

        {
            get_d2(self, other);

            if (!(m_gregorian_p(adat) == m_gregorian_p(bdat)))
                return equal_gen(self, other);

            {
                VALUE a_nth, b_nth;
                int a_jd, b_jd;

                m_canonicalize_jd(self, adat);
                m_canonicalize_jd(other, bdat);
                a_nth = m_nth(adat);
                b_nth = m_nth(bdat);
                a_jd = m_local_jd(adat);
                b_jd = m_local_jd(bdat);
                if (f_eqeq_p(a_nth, b_nth) &&
                    a_jd == b_jd)
                    return Qtrue;
                return Qfalse;
            }
        }
    }

d >> n → date click to toggle source

Returns a date object pointing `n` months after self. The argument `n` should be a numeric value.

    Date.new(2001,2,3)  >>  1   #=> #<Date: 2001-03-03 ...>
    Date.new(2001,2,3)  >> -2   #=> #<Date: 2000-12-03 ...>

When the same day does not exist for the corresponding month, the last day of the month is used instead:

    Date.new(2001,1,28) >> 1   #=> #<Date: 2001-02-28 ...>
    Date.new(2001,1,31) >> 1   #=> #<Date: 2001-02-28 ...>

This also results in the following, possibly unexpected, behavior:

    Date.new(2001,1,31) >> 2         #=> #<Date: 2001-03-31 ...>
    Date.new(2001,1,31) >> 1 >> 1    #=> #<Date: 2001-03-28 ...>

    Date.new(2001,1,31) >> 1 >> -1   #=> #<Date: 2001-01-28 ...>

    static VALUE
    d_lite_rshift(VALUE self, VALUE other)
    {
        VALUE t, y, nth, rjd2;
        int m, d, rjd;
        double sg;

        get_d1(self);
        t = f_add3(f_mul(m_real_year(dat), INT2FIX(12)),
                   INT2FIX(m_mon(dat) - 1),
                   other);
        if (FIXNUM_P(t)) {
            long it = FIX2LONG(t);
            y = LONG2NUM(DIV(it, 12));
            it = MOD(it, 12);
            m = (int)it + 1;
        }
        else {
            y = f_idiv(t, INT2FIX(12));
            t = f_mod(t, INT2FIX(12));
            m = FIX2INT(t) + 1;
        }
        d = m_mday(dat);
        sg = m_sg(dat);

        while (1) {
            int ry, rm, rd, ns;

            if (valid_civil_p(y, m, d, sg,
                              &nth, &ry,
                              &rm, &rd, &rjd, &ns))
                break;
            if (--d < 1)
                rb_raise(eDateError, "invalid date");
        }
        encode_jd(nth, rjd, &rjd2);
        return d_lite_plus(self, f_sub(rjd2, m_real_local_jd(dat)));
    }

ajd → rational click to toggle source

Returns the astronomical Julian day number. This is a fractional number, which is not adjusted by the offset.

    DateTime.new(2001,2,3,4,5,6,'+7').ajd     #=> (11769328217/4800)
    DateTime.new(2001,2,2,14,5,6,'-7').ajd    #=> (11769328217/4800)

    static VALUE
    d_lite_ajd(VALUE self)
    {
        get_d1(self);
        return m_ajd(dat);
    }

amjd → rational click to toggle source

Returns the astronomical modified Julian day number. This is a fractional number, which is not adjusted by the offset.

    DateTime.new(2001,2,3,4,5,6,'+7').amjd    #=> (249325817/4800)
    DateTime.new(2001,2,2,14,5,6,'-7').amjd   #=> (249325817/4800)

    static VALUE
    d_lite_amjd(VALUE self)
    {
        get_d1(self);
        return m_amjd(dat);
    }

as_json(*) click to toggle source

Returns a hash, that will be turned into a `JSON` object and represent this object.

    # File ext/json/lib/json/add/date.rb, line 19
    def as_json(*)
      {
        JSON.create_id => self.class.name,
        'y' => year,
        'm' => month,
        'd' => day,
        'sg' => start,
      }
    end

asctime → string click to toggle source

Returns a string in asctime(3) format (but without “n0” at the end). This method is equivalent to strftime('%c').

See also asctime(3) or ctime(3).

    static VALUE
    d_lite_asctime(VALUE self)
    {
        return strftimev("%a %b %e %H:%M:%S %Y", self, set_tmx);
    }

ctime → string click to toggle source

Returns a string in asctime(3) format (but without “n0” at the end). This method is equivalent to strftime('%c').

See also asctime(3) or ctime(3).

    static VALUE
    d_lite_asctime(VALUE self)
    {
        return strftimev("%a %b %e %H:%M:%S %Y", self, set_tmx);
    }

cwday → fixnum click to toggle source

Returns the day of calendar week (1-7, Monday is 1).

    Date.new(2001,2,3).cwday          #=> 6

    static VALUE
    d_lite_cwday(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_cwday(dat));
    }

cweek → fixnum click to toggle source

Returns the calendar week number (1-53).

    Date.new(2001,2,3).cweek          #=> 5

    static VALUE
    d_lite_cweek(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_cweek(dat));
    }

cwyear → integer click to toggle source

Returns the calendar week based year.

    Date.new(2001,2,3).cwyear         #=> 2001
    Date.new(2000,1,1).cwyear         #=> 1999

    static VALUE
    d_lite_cwyear(VALUE self)
    {
        get_d1(self);
        return m_real_cwyear(dat);
    }

day → fixnum click to toggle source

Returns the day of the month (1-31).

    Date.new(2001,2,3).mday           #=> 3

    static VALUE
    d_lite_mday(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_mday(dat));
    }

day_fraction → rational click to toggle source

Returns the fractional part of the day.

    DateTime.new(2001,2,3,12).day_fraction    #=> (1/2)

    static VALUE
    d_lite_day_fraction(VALUE self)
    {
        get_d1(self);
        if (simple_dat_p(dat))
            return INT2FIX(0);
        return m_fr(dat);
    }

downto(min) → enumerator click to toggle source
downto(min){|date| ...} → self

This method is equivalent to step(min, -1){|date| …}.

    static VALUE
    d_lite_downto(VALUE self, VALUE min)
    {
        VALUE date;

        RETURN_ENUMERATOR(self, 1, &min);

        date = self;
        while (FIX2INT(d_lite_cmp(date, min)) >= 0) {
            rb_yield(date);
            date = d_lite_plus(date, INT2FIX(-1));
        }
        return self;
    }

england → date click to toggle source

This method is equivalent to `new_start`(`Date::ENGLAND`).

    static VALUE
    d_lite_england(VALUE self)
    {
        return dup_obj_with_new_start(self, ENGLAND);
    }

fill() click to toggle source

    static VALUE
    d_lite_fill(VALUE self)
    {
        get_d1(self);

        if (simple_dat_p(dat)) {
            get_s_jd(dat);
            get_s_civil(dat);
        }
        else {
            get_c_jd(dat);
            get_c_civil(dat);
            get_c_df(dat);
            get_c_time(dat);
        }
        return self;
    }

friday? → bool click to toggle source

Returns true if the date is Friday.

    static VALUE
    d_lite_friday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 5);
    }

gregorian → date click to toggle source

This method is equivalent to `new_start`(`Date::GREGORIAN`).

    static VALUE
    d_lite_gregorian(VALUE self)
    {
        return dup_obj_with_new_start(self, GREGORIAN);
    }

gregorian? → bool click to toggle source

Returns true if the date is on or after the day of calendar reform.

    Date.new(1582,10,15).gregorian?          #=> true
    (Date.new(1582,10,15) - 1).gregorian?    #=> false

    static VALUE
    d_lite_gregorian_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_gregorian_p(dat));
    }

httpdate → string click to toggle source

This method is equivalent to strftime('%a, %d %b %Y %T GMT'). See also RFC 2616.

    static VALUE
    d_lite_httpdate(VALUE self)
    {
        volatile VALUE dup = dup_obj_with_new_offset(self, 0);
        return strftimev("%a, %d %b %Y %T GMT", dup, set_tmx);
    }

inspect → string click to toggle source

Returns the value as a string for inspection.

    Date.new(2001,2,3).inspect
              #=> "#<Date: 2001-02-03>"
    DateTime.new(2001,2,3,4,5,6,'-7').inspect
              #=> "#<DateTime: 2001-02-03T04:05:06-07:00>"

    static VALUE
    d_lite_inspect(VALUE self)
    {
        get_d1(self);
        return mk_inspect(dat, rb_obj_class(self), self);
    }

inspect_raw() click to toggle source

    static VALUE
    d_lite_inspect_raw(VALUE self)
    {
        get_d1(self);
        return mk_inspect_raw(dat, rb_obj_class(self));
    }

iso8601 → string click to toggle source
xmlschema → string

This method is equivalent to strftime('%F').

    static VALUE
    d_lite_iso8601(VALUE self)
    {
        return strftimev("%Y-%m-%d", self, set_tmx);
    }

italy → date click to toggle source

This method is equivalent to `new_start`(`Date::ITALY`).

    static VALUE
    d_lite_italy(VALUE self)
    {
        return dup_obj_with_new_start(self, ITALY);
    }

jd → integer click to toggle source

Returns the Julian day number. This is a whole number, which is adjusted by the offset as the local time.

    DateTime.new(2001,2,3,4,5,6,'+7').jd      #=> 2451944
    DateTime.new(2001,2,3,4,5,6,'-7').jd      #=> 2451944

    static VALUE
    d_lite_jd(VALUE self)
    {
        get_d1(self);
        return m_real_local_jd(dat);
    }

jisx0301 → string click to toggle source

Returns a string in a JIS X 0301 format.

    Date.new(2001,2,3).jisx0301       #=> "H13.02.03"

    static VALUE
    d_lite_jisx0301(VALUE self)
    {
        char fmtbuf[JISX0301_DATE_SIZE];
        const char *fmt;

        get_d1(self);
        fmt = jisx0301_date_format(fmtbuf, sizeof(fmtbuf),
                                   m_real_local_jd(dat),
                                   m_real_year(dat));
        return strftimev(fmt, self, set_tmx);
    }

julian → date click to toggle source

This method is equivalent to `new_start`(`Date::JULIAN`).

    static VALUE
    d_lite_julian(VALUE self)
    {
        return dup_obj_with_new_start(self, JULIAN);
    }

julian? → bool click to toggle source

Returns true if the date is before the day of calendar reform.

    Date.new(1582,10,15).julian?             #=> false
    (Date.new(1582,10,15) - 1).julian?       #=> true

    static VALUE
    d_lite_julian_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_julian_p(dat));
    }

ld → integer click to toggle source

Returns the Lilian day number. This is a whole number, which is adjusted by the offset as the local time.

    Date.new(2001,2,3).ld            #=> 152784

    static VALUE
    d_lite_ld(VALUE self)
    {
        get_d1(self);
        return f_sub(m_real_local_jd(dat), INT2FIX(2299160));
    }

leap? → bool click to toggle source

Returns true if the year is a leap year.

    Date.new(2000).leap?      #=> true
    Date.new(2001).leap?      #=> false

    static VALUE
    d_lite_leap_p(VALUE self)
    {
        int rjd, ns, ry, rm, rd;

        get_d1(self);
        if (m_gregorian_p(dat))
            return f_boolcast(c_gregorian_leap_p(m_year(dat)));

        c_civil_to_jd(m_year(dat), 3, 1, m_virtual_sg(dat),
                      &rjd, &ns);
        c_jd_to_civil(rjd - 1, m_virtual_sg(dat), &ry, &rm, &rd);
        return f_boolcast(rd == 29);
    }

marshal_dump_old() click to toggle source

    static VALUE
    d_lite_marshal_dump_old(VALUE self)
    {
        VALUE a;

        get_d1(self);

        a = rb_ary_new3(3,
                        m_ajd(dat),
                        m_of_in_day(dat),
                        DBL2NUM(m_sg(dat)));

        if (FL_TEST(self, FL_EXIVAR)) {
            rb_copy_generic_ivar(a, self);
            FL_SET(a, FL_EXIVAR);
        }

        return a;
    }

mday → fixnum click to toggle source

Returns the day of the month (1-31).

    Date.new(2001,2,3).mday           #=> 3

    static VALUE
    d_lite_mday(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_mday(dat));
    }

mjd → integer click to toggle source

Returns the modified Julian day number. This is a whole number, which is adjusted by the offset as the local time.

    DateTime.new(2001,2,3,4,5,6,'+7').mjd     #=> 51943
    DateTime.new(2001,2,3,4,5,6,'-7').mjd     #=> 51943

    static VALUE
    d_lite_mjd(VALUE self)
    {
        get_d1(self);
        return f_sub(m_real_local_jd(dat), INT2FIX(2400001));
    }

mon → fixnum click to toggle source
month → fixnum

Returns the month (1-12).

    Date.new(2001,2,3).mon            #=> 2

    static VALUE
    d_lite_mon(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_mon(dat));
    }

monday? → bool click to toggle source

Returns true if the date is Monday.

    static VALUE
    d_lite_monday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 1);
    }

month → fixnum click to toggle source

Returns the month (1-12).

    Date.new(2001,2,3).mon            #=> 2

    static VALUE
    d_lite_mon(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_mon(dat));
    }

new_start([start=Date::ITALY]) → date click to toggle source

Duplicates self and resets its day of calendar reform.

    d = Date.new(1582,10,15)
    d.new_start(Date::JULIAN)         #=> #<Date: 1582-10-05 ...>

    static VALUE
    d_lite_new_start(int argc, VALUE *argv, VALUE self)
    {
        VALUE vsg;
        double sg;

        rb_scan_args(argc, argv, "01", &vsg);

        sg = DEFAULT_SG;
        if (argc >= 1)
            val2sg(vsg, sg);

        return dup_obj_with_new_start(self, sg);
    }

next → date click to toggle source

Returns a date object denoting the following day.

    static VALUE
    d_lite_next(VALUE self)
    {
        return d_lite_next_day(0, (VALUE *)NULL, self);
    }

next_day([n=1]) → date click to toggle source

This method is equivalent to d + n.

    static VALUE
    d_lite_next_day(int argc, VALUE *argv, VALUE self)
    {
        VALUE n;

        rb_scan_args(argc, argv, "01", &n);
        if (argc < 1)
            n = INT2FIX(1);
        return d_lite_plus(self, n);
    }

next_month([n=1]) → date click to toggle source

This method is equivalent to d >> n.

See `Date#>>` for examples.

    static VALUE
    d_lite_next_month(int argc, VALUE *argv, VALUE self)
    {
        VALUE n;

        rb_scan_args(argc, argv, "01", &n);
        if (argc < 1)
            n = INT2FIX(1);
        return d_lite_rshift(self, n);
    }

next_year([n=1]) → date click to toggle source

This method is equivalent to d >> (n * 12).

    Date.new(2001,2,3).next_year      #=> #<Date: 2002-02-03 ...>
    Date.new(2008,2,29).next_year     #=> #<Date: 2009-02-28 ...>
    Date.new(2008,2,29).next_year(4)  #=> #<Date: 2012-02-29 ...>

See also `Date#>>`.

    static VALUE
    d_lite_next_year(int argc, VALUE *argv, VALUE self)
    {
        VALUE n;

        rb_scan_args(argc, argv, "01", &n);
        if (argc < 1)
            n = INT2FIX(1);
        return d_lite_rshift(self, f_mul(n, INT2FIX(12)));
    }

nth_kday?(p1, p2) click to toggle source

    static VALUE
    d_lite_nth_kday_p(VALUE self, VALUE n, VALUE k)
    {
        int rjd, ns;

        get_d1(self);

        if (NUM2INT(k) != m_wday(dat))
            return Qfalse;

        c_nth_kday_to_jd(m_year(dat), m_mon(dat),
                         NUM2INT(n), NUM2INT(k), m_virtual_sg(dat), /* !=m_sg() */
                         &rjd, &ns);
        if (m_local_jd(dat) != rjd)
            return Qfalse;
        return Qtrue;
    }

prev_day([n=1]) → date click to toggle source

This method is equivalent to d - n.

    static VALUE
    d_lite_prev_day(int argc, VALUE *argv, VALUE self)
    {
        VALUE n;

        rb_scan_args(argc, argv, "01", &n);
        if (argc < 1)
            n = INT2FIX(1);
        return d_lite_minus(self, n);
    }

prev_month([n=1]) → date click to toggle source

This method is equivalent to d << n.

See `Date#<<` for examples.

    static VALUE
    d_lite_prev_month(int argc, VALUE *argv, VALUE self)
    {
        VALUE n;

        rb_scan_args(argc, argv, "01", &n);
        if (argc < 1)
            n = INT2FIX(1);
        return d_lite_lshift(self, n);
    }

prev_year([n=1]) → date click to toggle source

This method is equivalent to d << (n * 12).

    Date.new(2001,2,3).prev_year      #=> #<Date: 2000-02-03 ...>
    Date.new(2008,2,29).prev_year     #=> #<Date: 2007-02-28 ...>
    Date.new(2008,2,29).prev_year(4)  #=> #<Date: 2004-02-29 ...>

See also `Date#<<`.

    static VALUE
    d_lite_prev_year(int argc, VALUE *argv, VALUE self)
    {
        VALUE n;

        rb_scan_args(argc, argv, "01", &n);
        if (argc < 1)
            n = INT2FIX(1);
        return d_lite_lshift(self, f_mul(n, INT2FIX(12)));
    }

rfc2822 → string click to toggle source
rfc822 → string

This method is equivalent to strftime('%a, %-d %b %Y %T %z').

    static VALUE
    d_lite_rfc2822(VALUE self)
    {
        return strftimev("%a, %-d %b %Y %T %z", self, set_tmx);
    }

rfc3339 → string click to toggle source

This method is equivalent to strftime('%FT%T%:z').

    static VALUE
    d_lite_rfc3339(VALUE self)
    {
        return strftimev("%Y-%m-%dT%H:%M:%S%:z", self, set_tmx);
    }

rfc2822 → string click to toggle source
rfc822 → string

This method is equivalent to strftime('%a, %-d %b %Y %T %z').

    static VALUE
    d_lite_rfc2822(VALUE self)
    {
        return strftimev("%a, %-d %b %Y %T %z", self, set_tmx);
    }

saturday? → bool click to toggle source

Returns true if the date is Saturday.

    static VALUE
    d_lite_saturday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 6);
    }

start → float click to toggle source

Returns the Julian day number denoting the day of calendar reform.

    Date.new(2001,2,3).start                  #=> 2299161.0
    Date.new(2001,2,3,Date::GREGORIAN).start  #=> -Infinity

    static VALUE
    d_lite_start(VALUE self)
    {
        get_d1(self);
        return DBL2NUM(m_sg(dat));
    }

step(limit[, step=1]) → enumerator click to toggle source
step(limit[, step=1]){|date| ...} → self

Iterates evaluation of the given block, which takes a date object. The limit should be a date object.

    Date.new(2001).step(Date.new(2001,-1,-1)).select{|d| d.sunday?}.size
                              #=> 52

    static VALUE
    d_lite_step(int argc, VALUE *argv, VALUE self)
    {
        VALUE limit, step, date;
        int c;

        rb_scan_args(argc, argv, "11", &limit, &step);

        if (argc < 2)
            step = INT2FIX(1);

    #if 0
        if (f_zero_p(step))
            rb_raise(rb_eArgError, "step can't be 0");
    #endif

        RETURN_ENUMERATOR(self, argc, argv);

        date = self;
        c = f_cmp(step, INT2FIX(0));
        if (c < 0) {
            while (FIX2INT(d_lite_cmp(date, limit)) >= 0) {
                rb_yield(date);
                date = d_lite_plus(date, step);
            }
        }
        else if (c == 0) {
            while (1)
                rb_yield(date);
        }
        else /* if (c > 0) */ {
            while (FIX2INT(d_lite_cmp(date, limit)) <= 0) {
                rb_yield(date);
                date = d_lite_plus(date, step);
            }
        }
        return self;
    }

strftime([format='%F']) → string click to toggle source

Formats date according to the directives in the given format string. The directives begin with a percent (%) character. Any text not listed as a directive will be passed through to the output string.

A directive consists of a percent (%) character, zero or more flags, an optional minimum field width, an optional modifier, and a conversion specifier as follows.

    %<flags><width><modifier><conversion>

Flags:

    -  don't pad a numerical output.
    _  use spaces for padding.
    0  use zeros for padding.
    ^  upcase the result string.
    #  change case.

The minimum field width specifies the minimum width.

The modifiers are “E”, “O”, “:”, “::” and “:::”. “E” and “O” are ignored. No effect to result currently.

Format directives:

    Date (Year, Month, Day):
      %Y - Year with century (can be negative, 4 digits at least)
              -0001, 0000, 1995, 2009, 14292, etc.
      %C - year / 100 (round down.  20 in 2009)
      %y - year % 100 (00..99)

      %m - Month of the year, zero-padded (01..12)
              %_m  blank-padded ( 1..12)
              %-m  no-padded (1..12)
      %B - The full month name (``January'')
              %^B  uppercased (``JANUARY'')
      %b - The abbreviated month name (``Jan'')
              %^b  uppercased (``JAN'')
      %h - Equivalent to %b

      %d - Day of the month, zero-padded (01..31)
              %-d  no-padded (1..31)
      %e - Day of the month, blank-padded ( 1..31)

      %j - Day of the year (001..366)

    Time (Hour, Minute, Second, Subsecond):
      %H - Hour of the day, 24-hour clock, zero-padded (00..23)
      %k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
      %I - Hour of the day, 12-hour clock, zero-padded (01..12)
      %l - Hour of the day, 12-hour clock, blank-padded ( 1..12)
      %P - Meridian indicator, lowercase (``am'' or ``pm'')
      %p - Meridian indicator, uppercase (``AM'' or ``PM'')

      %M - Minute of the hour (00..59)

      %S - Second of the minute (00..60)

      %L - Millisecond of the second (000..999)
      %N - Fractional seconds digits, default is 9 digits (nanosecond)
              %3N  millisecond (3 digits)   %15N femtosecond (15 digits)
              %6N  microsecond (6 digits)   %18N attosecond  (18 digits)
              %9N  nanosecond  (9 digits)   %21N zeptosecond (21 digits)
              %12N picosecond (12 digits)   %24N yoctosecond (24 digits)

    Time zone:
      %z - Time zone as hour and minute offset from UTC (e.g. +0900)
              %:z - hour and minute offset from UTC with a colon (e.g. +09:00)
              %::z - hour, minute and second offset from UTC (e.g. +09:00:00)
              %:::z - hour, minute and second offset from UTC
                                                (e.g. +09, +09:30, +09:30:30)
      %Z - Equivalent to %:z (e.g. +09:00)

    Weekday:
      %A - The full weekday name (``Sunday'')
              %^A  uppercased (``SUNDAY'')
      %a - The abbreviated name (``Sun'')
              %^a  uppercased (``SUN'')
      %u - Day of the week (Monday is 1, 1..7)
      %w - Day of the week (Sunday is 0, 0..6)

    ISO 8601 week-based year and week number:
    The week 1 of YYYY starts with a Monday and includes YYYY-01-04.
    The days in the year before the first week are in the last week of
    the previous year.
      %G - The week-based year
      %g - The last 2 digits of the week-based year (00..99)
      %V - Week number of the week-based year (01..53)

    Week number:
    The week 1 of YYYY starts with a Sunday or Monday (according to %U
    or %W).  The days in the year before the first week are in week 0.
      %U - Week number of the year.  The week starts with Sunday.  (00..53)
      %W - Week number of the year.  The week starts with Monday.  (00..53)

    Seconds since the Unix Epoch:
      %s - Number of seconds since 1970-01-01 00:00:00 UTC.
      %Q - Number of milliseconds since 1970-01-01 00:00:00 UTC.

    Literal string:
      %n - Newline character (\n)
      %t - Tab character (\t)
      %% - Literal ``%'' character

    Combination:
      %c - date and time (%a %b %e %T %Y)
      %D - Date (%m/%d/%y)
      %F - The ISO 8601 date format (%Y-%m-%d)
      %v - VMS date (%e-%b-%Y)
      %x - Same as %D
      %X - Same as %T
      %r - 12-hour time (%I:%M:%S %p)
      %R - 24-hour time (%H:%M)
      %T - 24-hour time (%H:%M:%S)
      %+ - date(1) (%a %b %e %H:%M:%S %Z %Y)

This method is similar to the strftime() function defined in ISO C and POSIX. Several directives (%a, %A, %b, %B, %c, %p, %r, %x, %X, %E*, %O* and %Z) are locale dependent in the function. However, this method is locale independent. So, the result may differ even if the same format string is used in other systems such as C. It is good practice to avoid %x and %X because there are corresponding locale independent representations, %D and %T.

Examples:

    d = DateTime.new(2007,11,19,8,37,48,"-06:00")
                              #=> #<DateTime: 2007-11-19T08:37:48-0600 ...>
    d.strftime("Printed on %m/%d/%Y")   #=> "Printed on 11/19/2007"
    d.strftime("at %I:%M%p")            #=> "at 08:37AM"

Various ISO 8601 formats:

    %Y%m%d           => 20071119                  Calendar date (basic)
    %F               => 2007-11-19                Calendar date (extended)
    %Y-%m            => 2007-11                   Calendar date, reduced accuracy, specific month
    %Y               => 2007                      Calendar date, reduced accuracy, specific year
    %C               => 20                        Calendar date, reduced accuracy, specific century
    %Y%j             => 2007323                   Ordinal date (basic)
    %Y-%j            => 2007-323                  Ordinal date (extended)
    %GW%V%u          => 2007W471                  Week date (basic)
    %G-W%V-%u        => 2007-W47-1                Week date (extended)
    %GW%V            => 2007W47                   Week date, reduced accuracy, specific week (basic)
    %G-W%V           => 2007-W47                  Week date, reduced accuracy, specific week (extended)
    %H%M%S           => 083748                    Local time (basic)
    %T               => 08:37:48                  Local time (extended)
    %H%M             => 0837                      Local time, reduced accuracy, specific minute (basic)
    %H:%M            => 08:37                     Local time, reduced accuracy, specific minute (extended)
    %H               => 08                        Local time, reduced accuracy, specific hour
    %H%M%S,%L        => 083748,000                Local time with decimal fraction, comma as decimal sign (basic)
    %T,%L            => 08:37:48,000              Local time with decimal fraction, comma as decimal sign (extended)
    %H%M%S.%L        => 083748.000                Local time with decimal fraction, full stop as decimal sign (basic)
    %T.%L            => 08:37:48.000              Local time with decimal fraction, full stop as decimal sign (extended)
    %H%M%S%z         => 083748-0600               Local time and the difference from UTC (basic)
    %T%:z            => 08:37:48-06:00            Local time and the difference from UTC (extended)
    %Y%m%dT%H%M%S%z  => 20071119T083748-0600      Date and time of day for calendar date (basic)
    %FT%T%:z         => 2007-11-19T08:37:48-06:00 Date and time of day for calendar date (extended)
    %Y%jT%H%M%S%z    => 2007323T083748-0600       Date and time of day for ordinal date (basic)
    %Y-%jT%T%:z      => 2007-323T08:37:48-06:00   Date and time of day for ordinal date (extended)
    %GW%V%uT%H%M%S%z => 2007W471T083748-0600      Date and time of day for week date (basic)
    %G-W%V-%uT%T%:z  => 2007-W47-1T08:37:48-06:00 Date and time of day for week date (extended)
    %Y%m%dT%H%M      => 20071119T0837             Calendar date and local time (basic)
    %FT%R            => 2007-11-19T08:37          Calendar date and local time (extended)
    %Y%jT%H%MZ       => 2007323T0837Z             Ordinal date and UTC of day (basic)
    %Y-%jT%RZ        => 2007-323T08:37Z           Ordinal date and UTC of day (extended)
    %GW%V%uT%H%M%z   => 2007W471T0837-0600        Week date and local time and difference from UTC (basic)
    %G-W%V-%uT%R%:z  => 2007-W47-1T08:37-06:00    Week date and local time and difference from UTC (extended)

See also strftime(3) and `::strptime`.

    static VALUE
    d_lite_strftime(int argc, VALUE *argv, VALUE self)
    {
        return date_strftime_internal(argc, argv, self,
                                      "%Y-%m-%d", set_tmx);
    }

succ → date click to toggle source

Returns a date object denoting the following day.

    static VALUE
    d_lite_next(VALUE self)
    {
        return d_lite_next_day(0, (VALUE *)NULL, self);
    }

sunday? → bool click to toggle source

Returns true if the date is Sunday.

    static VALUE
    d_lite_sunday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 0);
    }

thursday? → bool click to toggle source

Returns true if the date is Thursday.

    static VALUE
    d_lite_thursday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 4);
    }

to_date → self click to toggle source

Returns self.

    static VALUE
    date_to_date(VALUE self)
    {
        return self;
    }

to_datetime → datetime click to toggle source

Returns a `DateTime` object which denotes self.

    static VALUE
    date_to_datetime(VALUE self)
    {
        get_d1a(self);

        if (simple_dat_p(adat)) {
            VALUE new = d_lite_s_alloc_simple(cDateTime);
            {
                get_d1b(new);
                bdat->s = adat->s;
                return new;
            }
        }
        else {
            VALUE new = d_lite_s_alloc_complex(cDateTime);
            {
                get_d1b(new);
                bdat->c = adat->c;
                bdat->c.df = 0;
                RB_OBJ_WRITE(new, &bdat->c.sf, INT2FIX(0));
    #ifndef USE_PACK
                bdat->c.hour = 0;
                bdat->c.min = 0;
                bdat->c.sec = 0;
    #else
                bdat->c.pc = PACK5(EX_MON(adat->c.pc), EX_MDAY(adat->c.pc),
                                   0, 0, 0);
                bdat->c.flags |= HAVE_DF | HAVE_TIME;
    #endif
                return new;
            }
        }
    }

to_json(*args) click to toggle source

Stores class name (`Date`) with Julian year `y`, month `m`, day `d` and Day of Calendar Reform `sg` as `JSON` string

    # File ext/json/lib/json/add/date.rb, line 31
    def to_json(*args)
      as_json.to_json(*args)
    end

to_s → string click to toggle source

Returns a string in an ISO 8601 format. (This method doesn't use the expanded representations.)

    Date.new(2001,2,3).to_s  #=> "2001-02-03"

    static VALUE
    d_lite_to_s(VALUE self)
    {
        return strftimev("%Y-%m-%d", self, set_tmx);
    }

to_time → time click to toggle source

Returns a `Time` object which denotes self. If self is a julian date, convert it to a gregorian date before converting it to `Time`.

    static VALUE
    date_to_time(VALUE self)
    {
        get_d1a(self);

        if (m_julian_p(adat)) {
            VALUE tmp = d_lite_gregorian(self);
            get_d1b(tmp);
            adat = bdat;
        }

        return f_local3(rb_cTime,
            m_real_year(adat),
            INT2FIX(m_mon(adat)),
            INT2FIX(m_mday(adat)));
    }

tuesday? → bool click to toggle source

Returns true if the date is Tuesday.

    static VALUE
    d_lite_tuesday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 2);
    }

upto(max) → enumerator click to toggle source
upto(max){|date| ...} → self

This method is equivalent to step(max, 1){|date| …}.

    static VALUE
    d_lite_upto(VALUE self, VALUE max)
    {
        VALUE date;

        RETURN_ENUMERATOR(self, 1, &max);

        date = self;
        while (FIX2INT(d_lite_cmp(date, max)) <= 0) {
            rb_yield(date);
            date = d_lite_plus(date, INT2FIX(1));
        }
        return self;
    }

wday → fixnum click to toggle source

Returns the day of week (0-6, Sunday is zero).

    Date.new(2001,2,3).wday           #=> 6

    static VALUE
    d_lite_wday(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_wday(dat));
    }

wednesday? → bool click to toggle source

Returns true if the date is Wednesday.

    static VALUE
    d_lite_wednesday_p(VALUE self)
    {
        get_d1(self);
        return f_boolcast(m_wday(dat) == 3);
    }

iso8601 → string click to toggle source
xmlschema → string

This method is equivalent to strftime('%F').

    static VALUE
    d_lite_iso8601(VALUE self)
    {
        return strftimev("%Y-%m-%d", self, set_tmx);
    }

yday → fixnum click to toggle source

Returns the day of the year (1-366).

    Date.new(2001,2,3).yday           #=> 34

    static VALUE
    d_lite_yday(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_yday(dat));
    }

year → integer click to toggle source

Returns the year.

    Date.new(2001,2,3).year           #=> 2001
    (Date.new(1,1,1) - 1).year        #=> 0

    static VALUE
    d_lite_year(VALUE self)
    {
        get_d1(self);
        return m_real_year(dat);
    }

### Private Instance Methods

hour() click to toggle source

    static VALUE
    d_lite_zero(VALUE x)
    {
        return INT2FIX(0);
    }

min() click to toggle source

    static VALUE
    d_lite_zero(VALUE x)
    {
        return INT2FIX(0);
    }

minute() click to toggle source

    static VALUE
    d_lite_zero(VALUE x)
    {
        return INT2FIX(0);
    }

sec() click to toggle source

    static VALUE
    d_lite_zero(VALUE x)
    {
        return INT2FIX(0);
    }

second() click to toggle source

    static VALUE
    d_lite_zero(VALUE x)
    {
        return INT2FIX(0);
    }

wnum0() click to toggle source

    static VALUE
    d_lite_wnum0(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_wnum0(dat));
    }

wnum1() click to toggle source

    static VALUE
    d_lite_wnum1(VALUE self)
    {
        get_d1(self);
        return INT2FIX(m_wnum1(dat));
    }