class Date

Class Date provides methods for storing and manipulating calendar dates.

Consider using class Time instead of class Date if:

You need both dates and times; Date handles only dates.
You need only Gregorian dates (and not Julian dates); see Julian and Gregorian Calendars.

A Date object, once created, is immutable, and cannot be modified.

Creating a Date¶ ↑

You can create a date for the current date, using Date.today:

Date.today # => #<Date: 1999-12-31>

You can create a specific date from various combinations of arguments:

Date.new takes integer year, month, and day-of-month:

Date.new(1999, 12, 31) # => #<Date: 1999-12-31>

Date.ordinal takes integer year and day-of-year:

Date.ordinal(1999, 365) # => #<Date: 1999-12-31>

Date.jd takes integer Julian day:

Date.jd(2451544) # => #<Date: 1999-12-31>

Date.commercial takes integer commercial data (year, week, day-of-week):
```
Date.commercial(1999, 52, 5) # => #<Date: 1999-12-31>
```

Date.parse takes a string, which it parses heuristically:

Date.parse('1999-12-31')    # => #<Date: 1999-12-31>
Date.parse('31-12-1999')    # => #<Date: 1999-12-31>
Date.parse('1999-365')      # => #<Date: 1999-12-31>
Date.parse('1999-W52-5')    # => #<Date: 1999-12-31>

Date.strptime takes a date string and a format string, then parses the date string according to the format string:

Date.strptime('1999-12-31', '%Y-%m-%d')  # => #<Date: 1999-12-31>
Date.strptime('31-12-1999', '%d-%m-%Y')  # => #<Date: 1999-12-31>
Date.strptime('1999-365', '%Y-%j')       # => #<Date: 1999-12-31>
Date.strptime('1999-W52-5', '%G-W%V-%u') # => #<Date: 1999-12-31>
Date.strptime('1999 52 5', '%Y %U %w')   # => #<Date: 1999-12-31>
Date.strptime('1999 52 5', '%Y %W %u')   # => #<Date: 1999-12-31>
Date.strptime('fri31dec99', '%a%d%b%y')  # => #<Date: 1999-12-31>

See also the specialized methods in “Specialized Format Strings” in Formats for Dates and Times

Argument `limit`¶ ↑

Certain singleton methods in Date that parse string arguments also take optional keyword argument limit, which can limit the length of the string argument.

When limit is:

Non-negative: raises ArgumentError if the string length is greater than limit.
Other numeric or nil: ignores limit.
Other non-numeric: raises TypeError.

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

Returns a hash of values parsed from string, which should be a valid HTTP date format:

d = Date.new(2001, 2, 3)
s = d.httpdate # => "Sat, 03 Feb 2001 00:00:00 GMT"
Date._httpdate(s)
# => {:wday=>6, :mday=>3, :mon=>2, :year=>2001, :hour=>0, :min=>0, :sec=>0, :zone=>"GMT", :offset=>0}

Related: Date.httpdate (returns a Date object).

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

Returns a hash of values parsed from string, which should contain an ISO 8601 formatted date:

d = Date.new(2001, 2, 3)
s = d.iso8601    # => "2001-02-03"
Date._iso8601(s) # => {:mday=>3, :year=>2001, :mon=>2}

See argument limit.

Related: Date.iso8601 (returns a Date object).

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

Returns a hash of values parsed from string, which should be a valid JIS X 0301 date format:

d = Date.new(2001, 2, 3)
s = d.jisx0301    # => "H13.02.03"
Date._jisx0301(s) # => {:year=>2001, :mon=>2, :mday=>3}

See argument limit.

Related: Date.jisx0301 (returns a Date object).

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

Note: This method recognizes many forms in string, but it is not a validator. For formats, see “Specialized Format Strings” in Formats for Dates and Times

If string does not specify a valid date, the result is unpredictable; consider using Date._strptime instead.

Returns a hash of values parsed from string:

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

If comp is true and the given year is in the range (0..99), the current century is supplied; otherwise, the year is taken as given:

Date._parse('01-02-03', true)  # => {:year=>2001, :mon=>2, :mday=>3}
Date._parse('01-02-03', false) # => {:year=>1, :mon=>2, :mday=>3}

See argument limit.

Related: Date.parse(returns a Date object).

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

_rfc2822(string, limit: 128) → hash

Returns a hash of values parsed from string, which should be a valid RFC 2822 date format:

d = Date.new(2001, 2, 3)
s = d.rfc2822 # => "Sat, 3 Feb 2001 00:00:00 +0000"
Date._rfc2822(s)
# => {:wday=>6, :mday=>3, :mon=>2, :year=>2001, :hour=>0, :min=>0, :sec=>0, :zone=>"+0000", :offset=>0}

See argument limit.

Related: Date.rfc2822 (returns a Date object).

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

Returns a hash of values parsed from string, which should be a valid RFC 3339 format:

d = Date.new(2001, 2, 3)
s = d.rfc3339     # => "2001-02-03T00:00:00+00:00"
Date._rfc3339(s)
# => {:year=>2001, :mon=>2, :mday=>3, :hour=>0, :min=>0, :sec=>0, :zone=>"+00:00", :offset=>0}

See argument limit.

Related: Date.rfc3339 (returns a Date object).

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);
}

_rfc2822(string, limit: 128) → hash

Returns a hash of values parsed from string, which should be a valid RFC 2822 date format:

d = Date.new(2001, 2, 3)
s = d.rfc2822 # => "Sat, 3 Feb 2001 00:00:00 +0000"
Date._rfc2822(s)
# => {:wday=>6, :mday=>3, :mon=>2, :year=>2001, :hour=>0, :min=>0, :sec=>0, :zone=>"+0000", :offset=>0}

See argument limit.

Related: Date.rfc2822 (returns a Date object).

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

Returns a hash of values parsed from string according to the given format:

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

For other formats, see Formats for Dates and Times. (Unlike Date.strftime, does not support flags and width.)

See also strptime(3).

Related: Date.strptime (returns a Date object).

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

Returns a hash of values parsed from string, which should be a valid XML date format:

d = Date.new(2001, 2, 3)
s = d.xmlschema    # => "2001-02-03"
Date._xmlschema(s) # => {:year=>2001, :mon=>2, :mday=>3}

See argument limit.

Related: Date.xmlschema (returns a Date object).

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 (*args)

Same as Date.new.

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

Returns a new Date object constructed from the arguments.

Argument cwyear gives the year, and should be an integer.

Argument cweek gives the index of the week within the year, and should be in range (1..53) or (-53..-1); in some years, 53 or -53 will be out-of-range; if negative, counts backward from the end of the year:

Date.commercial(2022, 1, 1).to_s  # => "2022-01-03"
Date.commercial(2022, 52, 1).to_s # => "2022-12-26"

Argument cwday gives the indes of the weekday within the week, and should be in range (1..7) or (-7..-1); 1 or -7 is Monday; if negative, counts backward from the end of the week:

Date.commercial(2022, 1, 1).to_s  # => "2022-01-03"
Date.commercial(2022, 1, -7).to_s # => "2022-01-03"

When cweek is 1:

If January 1 is a Friday, Saturday, or Sunday, the first week begins in the week after:

Date::ABBR_DAYNAMES[Date.new(2023, 1, 1).wday] # => "Sun"
Date.commercial(2023, 1, 1).to_s # => "2023-01-02"
Date.commercial(2023, 1, 7).to_s # => "2023-01-08"

Otherwise, the first week is the week of January 1, which may mean some of the days fall on the year before:

Date::ABBR_DAYNAMES[Date.new(2020, 1, 1).wday] # => "Wed"
Date.commercial(2020, 1, 1).to_s # => "2019-12-30"
Date.commercial(2020, 1, 7).to_s # => "2020-01-05"

See argument start.

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) → true or false

Returns true if the given year is a leap year in the proleptic Gregorian calendar, false otherwise:

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

Related: Date.julian_leap?.

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

Returns a new Date object with values parsed from string, which should be a valid HTTP date format:

d = Date.new(2001, 2, 3)
s = d.httpdate   # => "Sat, 03 Feb 2001 00:00:00 GMT"
Date.httpdate(s) # => #<Date: 2001-02-03>

See:

Argument start.
Argument limit.

Related: Date._httpdate (returns a hash).

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], hash;
        argv2[0] = str;
        if (!NIL_P(opt)) argv2[argc2++] = opt;
        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

Returns a new Date object with values parsed from string, which should contain an ISO 8601 formatted date:

d = Date.new(2001, 2, 3)
s = d.iso8601   # => "2001-02-03"
Date.iso8601(s) # => #<Date: 2001-02-03>

See:

Argument start.
Argument limit.

Related: Date._iso8601 (returns a hash).

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

jd(jd = 0, start = Date::ITALY) → date

Returns a new Date object formed from the arguments:

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

The returned date is:

Gregorian, if the argument is greater than or equal to start:

Date::ITALY                         # => 2299161
Date.jd(Date::ITALY).gregorian?     # => true
Date.jd(Date::ITALY + 1).gregorian? # => true

Julian, otherwise

Date.jd(Date::ITALY - 1).julian?    # => true

See argument start.

Related: Date.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

Returns a new Date object with values parsed from string, which should be a valid JIS X 0301 format:

d = Date.new(2001, 2, 3)
s = d.jisx0301   # => "H13.02.03"
Date.jisx0301(s) # => #<Date: 2001-02-03>

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

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

See:

Argument start.
Argument limit.

Related: Date._jisx0301 (returns a hash).

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

json_create (object)

See as_json.

# File ext/json/lib/json/add/date.rb, line 10
def self.json_create(object)
  civil(*object.values_at('y', 'm', 'd', 'sg'))
end

julian_leap?(year) → true or false

Returns true if the given year is a leap year in the proleptic Julian calendar, false otherwise:

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

Related: Date.gregorian_leap?.

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));
}

gregorian_leap?(year) → true or false

Returns true if the given year is a leap year in the proleptic Gregorian calendar, false otherwise:

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

Related: Date.julian_leap?.

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(year = -4712, month = 1, mday = 1, start = Date::ITALY) → date

Returns a new Date object constructed from the given arguments:

Date.new(2022).to_s        # => "2022-01-01"
Date.new(2022, 2).to_s     # => "2022-02-01"
Date.new(2022, 2, 4).to_s  # => "2022-02-04"

Argument month should be in range (1..12) or range (-12..-1); when the argument is negative, counts backward from the end of the year:

Date.new(2022, -11, 4).to_s # => "2022-02-04"

Argument mday should be in range (1..n) or range (-n..-1) where n is the number of days in the month; when the argument is negative, counts backward from the end of the month.

See argument start.

Related: Date.jd.

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;
}

ordinal(year = -4712, yday = 1, start = Date::ITALY) → date

Returns a new Date object formed fom the arguments.

With no arguments, returns the date for January 1, -4712:

Date.ordinal.to_s # => "-4712-01-01"

With argument year, returns the date for January 1 of that year:

Date.ordinal(2001).to_s  # => "2001-01-01"
Date.ordinal(-2001).to_s # => "-2001-01-01"

With positive argument yday == n, returns the date for the nth day of the given year:

Date.ordinal(2001, 14).to_s # => "2001-01-14"

With negative argument yday, counts backward from the end of the year:

Date.ordinal(2001, -14).to_s # => "2001-12-18"

Raises an exception if yday is zero or out of range.

See argument start.

Related: Date.jd, Date.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

Note: This method recognizes many forms in string, but it is not a validator. For formats, see “Specialized Format Strings” in Formats for Dates and Times If string does not specify a valid date, the result is unpredictable; consider using Date._strptime instead.

Returns a new Date object with values parsed from string:

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>

If comp is true and the given year is in the range (0..99), the current century is supplied; otherwise, the year is taken as given:

Date.parse('01-02-03', true)  # => #<Date: 2001-02-03>
Date.parse('01-02-03', false) # => #<Date: 0001-02-03>

See:

Argument start.
Argument limit.

Related: Date._parse (returns a hash).

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], hash;
        argv2[0] = str;
        argv2[1] = comp;
        if (!NIL_P(opt)) argv2[argc2++] = opt;
        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

Returns a new Date object with values parsed from string, which should be a valid RFC 2822 date format:

d = Date.new(2001, 2, 3)
s = d.rfc2822   # => "Sat, 3 Feb 2001 00:00:00 +0000"
Date.rfc2822(s) # => #<Date: 2001-02-03>

See:

Argument start.
Argument limit.

Related: Date._rfc2822 (returns a hash).

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], hash;
        argv2[0] = str;
        if (!NIL_P(opt)) argv2[argc2++] = opt;
        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

Returns a new Date object with values parsed from string, which should be a valid RFC 3339 format:

d = Date.new(2001, 2, 3)
s = d.rfc3339   # => "2001-02-03T00:00:00+00:00"
Date.rfc3339(s) # => #<Date: 2001-02-03>

See:

Argument start.
Argument limit.

Related: Date._rfc3339 (returns a hash).

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], hash;
        argv2[0] = str;
        if (!NIL_P(opt)) argv2[argc2++] = opt;
        hash = date_s__rfc3339(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

Returns a new Date object with values parsed from string, which should be a valid RFC 2822 date format:

d = Date.new(2001, 2, 3)
s = d.rfc2822   # => "Sat, 3 Feb 2001 00:00:00 +0000"
Date.rfc2822(s) # => #<Date: 2001-02-03>

See:

Argument start.
Argument limit.

Related: Date._rfc2822 (returns a hash).

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], hash;
        argv2[0] = str;
        if (!NIL_P(opt)) argv2[argc2++] = opt;
        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

Returns a new Date object with values parsed from string, according to the given format:

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>

For other formats, see Formats for Dates and Times. (Unlike Date.strftime, does not support flags and width.)

See argument start.

Public Instance Methods

d + other → date

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

If the other is a date object, returns a Rational whose value is the difference between the two dates in days. 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

Returns a new Date object representing the date n months earlier; n should be a numeric:

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

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

(Date.new(2001, 3, 31) << 1).to_s  # => "2001-02-28"
(Date.new(2001, 3, 31) << -6).to_s # => "2001-09-30"

This results in the following, possibly unexpected, behaviors:

d0 = Date.new(2001, 3, 31)
d0 << 2      # => #<Date: 2001-01-31>
d0 << 1 << 1 # => #<Date: 2001-01-28>

d0 = Date.new(2001, 3, 31)
d1 = d0 << 1  # => #<Date: 2001-02-28>
d2 = d1 << -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));
}

self <=> other → -1, 0, 1 or nil

Compares self and other, returning:

-1 if other is larger.
0 if the two are equal.
1 if other is smaller.
nil if the two are incomparable.

Argument other may be:

Another Date object:

d = Date.new(2022, 7, 27) # => #<Date: 2022-07-27 ((2459788j,0s,0n),+0s,2299161j)>
prev_date = d.prev_day    # => #<Date: 2022-07-26 ((2459787j,0s,0n),+0s,2299161j)>
next_date = d.next_day    # => #<Date: 2022-07-28 ((2459789j,0s,0n),+0s,2299161j)>
d <=> next_date           # => -1
d <=> d                   # => 0
d <=> prev_date           # => 1

A DateTime object:

d <=> DateTime.new(2022, 7, 26) # => 1
d <=> DateTime.new(2022, 7, 27) # => 0
d <=> DateTime.new(2022, 7, 28) # => -1

A numeric (compares self.ajd to other):

d <=> 2459788 # => -1
d <=> 2459787 # => 1
d <=> 2459786 # => 1
d <=> d.ajd   # => 0

Any other object:
```
d <=> Object.new # => nil
```

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);
            }
        }
    }
}

self === other → true, false, or nil.

Returns true if self and other represent the same date, false if not, nil if the two are not comparable.

Argument other may be:

Another Date object:

d = Date.new(2022, 7, 27) # => #<Date: 2022-07-27 ((2459788j,0s,0n),+0s,2299161j)>
prev_date = d.prev_day    # => #<Date: 2022-07-26 ((2459787j,0s,0n),+0s,2299161j)>
next_date = d.next_day    # => #<Date: 2022-07-28 ((2459789j,0s,0n),+0s,2299161j)>
d === prev_date           # => false
d === d                   # => true
d === next_date           # => false

A DateTime object:

d === DateTime.new(2022, 7, 26) # => false
d === DateTime.new(2022, 7, 27) # => true
d === DateTime.new(2022, 7, 28) # => false

A numeric (compares self.jd to other):

d === 2459788 # => true
d === 2459787 # => false
d === 2459786 # => false
d === d.jd    # => true

An object not comparable:
```
d === Object.new # => nil
```

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 → new_date

Returns a new Date object representing the date n months later; n should be a numeric:

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

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

(Date.new(2001, 1, 31) >> 1).to_s  # => "2001-02-28"
(Date.new(2001, 1, 31) >> -4).to_s # => "2000-09-30"

This results in the following, possibly unexpected, behaviors:

d0 = Date.new(2001, 1, 31)
d1 = d0 >> 1 # => #<Date: 2001-02-28>
d2 = d1 >> 1 # => #<Date: 2001-03-28>

d0 = Date.new(2001, 1, 31)
d1 = d0 >> 1  # => #<Date: 2001-02-28>
d2 = d1 >> -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

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

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 (*)

Methods Date#as_json and Date.json_create may be used to serialize and deserialize a Date object; see Marshal.

Method Date#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/date'
x = Date.today.as_json
# => {"json_class"=>"Date", "y"=>2023, "m"=>11, "d"=>21, "sg"=>2299161.0}

Method JSON.create deserializes such a hash, returning a Date object:

Date.json_create(x)
# => #<Date: 2023-11-21 ((2460270j,0s,0n),+0s,2299161j)>

# File ext/json/lib/json/add/date.rb, line 32
def as_json(*)
  {
    JSON.create_id => self.class.name,
    'y' => year,
    'm' => month,
    'd' => day,
    'sg' => start,
  }
end

asctime

Also aliased as: ctime

ctime

Alias for: asctime

cwday → integer

Returns the commercial-date weekday index for self (see Date.commercial); 1 is Monday:

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

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

cweek → integer

Returns commercial-date week index for self (see Date.commercial):

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

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

cwyear → integer

Returns commercial-date year for self (see Date.commercial):

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

Alias for: mday

day_fraction → rational

Returns the fractional part of the day in range (Rational(0, 1)…Rational(1, 1)):

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);
}

deconstruct_keys(array_of_names_or_nil) → hash

Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year, :month, :day, :wday, :yday.

Possible usages:

d = Date.new(2022, 10, 5)

if d in wday: 3, day: ..7  # uses deconstruct_keys underneath
  puts "first Wednesday of the month"
end
#=> prints "first Wednesday of the month"

case d
in year: ...2022
  puts "too old"
in month: ..9
  puts "quarter 1-3"
in wday: 1..5, month:
  puts "working day in month #{month}"
end
#=> prints "working day in month 10"

Note that deconstruction by pattern can also be combined with class check:

if d in Date(wday: 3, day: ..7)
  puts "first Wednesday of the month"
end

static VALUE
d_lite_deconstruct_keys(VALUE self, VALUE keys)
{
    return deconstruct_keys(self, keys, /* is_datetime=false */ 0);
}

downto(min){|date| ... } → self

Equivalent to step with arguments min and -1.

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 → new_date

Equivalent to Date#new_start with argument Date::ENGLAND.

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

friday? → true or false

Returns true if self is a Friday, false otherwise.

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

gregorian → new_date

Equivalent to Date#new_start with argument Date::GREGORIAN.

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

gregorian? → true or false

Returns true if the date is on or after the date of calendar reform, false otherwise:

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

Equivalent to strftime with argument '%a, %d %b %Y %T GMT'; see Formats for Dates and Times:

Date.new(2001, 2, 3).httpdate # => "Sat, 03 Feb 2001 00:00:00 GMT"

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);
}

infinite? → false

Returns false

# File ext/date/lib/date.rb, line 13
def infinite?
  false
end

inspect → string

Returns a string representation of self:

Date.new(2001, 2, 3).inspect
# => "#<Date: 2001-02-03 ((2451944j,0s,0n),+0s,2299161j)>"

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

iso8601 → string

Equivalent to strftime with argument '%Y-%m-%d' (or its shorthand form '%F');

Date.new(2001, 2, 3).iso8601 # => "2001-02-03"

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

Also aliased as: xmlschema

italy → new_date

Equivalent to Date#new_start with argument Date::ITALY.

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

jd → integer

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

Returns a string representation of the date in self in 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 → new_date

Equivalent to Date#new_start with argument Date::JULIAN.

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

julian? → true or false

Returns true if the date is before the date of calendar reform, false otherwise:

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

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

ld → integer

Returns the Lilian day number, which is the number of days since the beginning of the Gregorian calendar, October 15, 1582.

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? → true or false

Returns true if the year is a leap year, false otherwise:

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);
}

mday

Also aliased as: day

mjd → integer

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 → integer

Returns the month in range (1..12):

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

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

Also aliased as: month

monday? → true or false

Returns true if self is a Monday, false otherwise.

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

month

Alias for: mon

new_start(start = Date::ITALY]) → new_date

Returns a copy of self with the given start value:

d0 = Date.new(2000, 2, 3)
d0.julian? # => false
d1 = d0.new_start(Date::JULIAN)
d1.julian? # => true

See argument start.

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 → new_date

Returns a new Date object representing the following day:

d = Date.new(2001, 2, 3)
d.to_s      # => "2001-02-03"
d.next.to_s # => "2001-02-04"

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

Also aliased as: succ

next_day(n = 1) → new_date

Equivalent to Date#+ with argument 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) → new_date

Equivalent to >> with argument n.

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) → new_date

Equivalent to >> with argument n * 12.

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)));
}

prev_day(n = 1) → new_date

Equivalent to Date#- with argument 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) → new_date

Equivalent to << with argument n.

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) → new_date

Equivalent to << with argument n * 12.

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

Equivalent to strftime with argument '%a, %-d %b %Y %T %z'; see Formats for Dates and Times:

Date.new(2001, 2, 3).rfc2822 # => "Sat, 3 Feb 2001 00:00:00 +0000"

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

Also aliased as: rfc822, rfc822

rfc3339 → string

Equivalent to strftime with argument '%FT%T%:z'; see Formats for Dates and Times:

Date.new(2001, 2, 3).rfc3339 # => "2001-02-03T00:00:00+00:00"

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

rfc822

Alias for: rfc2822

saturday? → true or false

Returns true if self is a Saturday, false otherwise.

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

start → float

Returns the Julian start date for calendar reform; if not an infinity, the returned value is suitable for passing to Date#jd:

d = Date.new(2001, 2, 3, Date::ITALY)
s = d.start     # => 2299161.0
Date.jd(s).to_s # => "1582-10-15"

d = Date.new(2001, 2, 3, Date::ENGLAND)
s = d.start     # => 2361222.0
Date.jd(s).to_s # => "1752-09-14"

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

See argument start.

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

step(limit, step = 1){|date| ... } → self

Calls the block with specified dates; returns self.

The first date is self.
Each successive date is date + step, where step is the numeric step size in days.
The last date is the last one that is before or equal to limit, which should be a Date object.

Example:

limit = Date.new(2001, 12, 31)
Date.new(2001).step(limit){|date| p date.to_s if date.mday == 31 }

Output:

"2001-01-31"
"2001-03-31"
"2001-05-31"
"2001-07-31"
"2001-08-31"
"2001-10-31"
"2001-12-31"

Returns an Enumerator if no block is given.

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

Returns a string representation of the date in self, formatted according the given format:

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

For other formats, see Formats for Dates and Times.

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

succ

Alias for: next

sunday? → true or false

Returns true if self is a Sunday, false otherwise.

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

thursday? → true or false

Returns true if self is a Thursday, false otherwise.

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

to_date → self

Returns self.

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

to_datetime → datetime

Returns a DateTime whose value is the same as self:

Date.new(2001, 2, 3).to_datetime # => #<DateTime: 2001-02-03T00:00:00+00:00>

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)

Returns a JSON string representing self:

require 'json/add/date'
puts Date.today.to_json

Output:

{"json_class":"Date","y":2023,"m":11,"d":21,"sg":2299161.0}

# File ext/json/lib/json/add/date.rb, line 51
def to_json(*args)
  as_json.to_json(*args)
end

to_s → string

Returns a string representation of the date in self in ISO 8601 extended date format ('%Y-%m-%d'):

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

Returns a new Time object with the same value as self; if self is a Julian date, derives its Gregorian date for conversion to the Time object:

Date.new(2001, 2, 3).to_time               # => 2001-02-03 00:00:00 -0600
Date.new(2001, 2, 3, Date::JULIAN).to_time # => 2001-02-16 00:00:00 -0600

static VALUE
date_to_time(VALUE self)
{
    VALUE t;

    get_d1a(self);

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

    t = f_local3(rb_cTime,
        m_real_year(adat),
        INT2FIX(m_mon(adat)),
        INT2FIX(m_mday(adat)));
    RB_GC_GUARD(self); /* may be the converted gregorian */
    return t;
}

tuesday? → true or false

Returns true if self is a Tuesday, false otherwise.

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

upto(max){|date| ... } → self

Equivalent to step with arguments max and 1.

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 → integer

Returns the day of week in range (0..6); Sunday is 0:

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

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

wednesday? → true or false

Returns true if self is a Wednesday, false otherwise.

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

xmlschema

Alias for: iso8601

yday → integer

Returns the day of the year, in range (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

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);
}

class Date

Creating a Date¶ ↑

Argument limit¶ ↑

Argument `limit`¶ ↑