Class: DateTime
| Relationships & Source Files | |
| Super Chains via Extension / Inclusion / Inheritance | |
| Class Chain: 
          self,
          ::Date
         | |
| Instance Chain: 
          self,
          ::Date,
          Comparable
         | |
| Inherits: | Date | 
| Defined in: | ext/date/date_core.c | 
Overview
A subclass of ::Date that easily handles date, hour, minute, second, and offset.
DateTime does not consider any leap seconds, does not track any summer time rules.
A DateTime object is created with .new, .jd, .ordinal, .commercial, .parse, .strptime, .now, Time#to_datetime, etc.
require 'date'
DateTime.new(2001,2,3,4,5,6)
                    #=> #<DateTime: 2001-02-03T04:05:06+00:00 ...>The last element of day, hour, minute, or second can be a fractional number. The fractional number's precision is assumed at most nanosecond.
DateTime.new(2001,2,3.5)
                    #=> #<DateTime: 2001-02-03T12:00:00+00:00 ...>An optional argument, the offset, indicates the difference between the local time and UTC. For example, Rational(3,24) represents ahead of 3 hours of UTC, Rational(-5,24) represents behind of 5 hours of UTC. The offset should be -1 to +1, and its precision is assumed at most second. The default value is zero (equals to UTC).
DateTime.new(2001,2,3,4,5,6,Rational(3,24))
                    #=> #<DateTime: 2001-02-03T04:05:06+03:00 ...>The offset also accepts string form:
DateTime.new(2001,2,3,4,5,6,'+03:00')
                    #=> #<DateTime: 2001-02-03T04:05:06+03:00 ...>An optional argument, the day of calendar reform (start), denotes a Julian day number, which should be 2298874 to 2426355 or negative/positive infinity. The default value is Date::ITALY (2299161=1582-10-15).
A DateTime object has various methods. See each reference.
d = DateTime.parse('3rd Feb 2001 04:05:06+03:30')
                    #=> #<DateTime: 2001-02-03T04:05:06+03:30 ...>
d.hour              #=> 4
d.min               #=> 5
d.sec               #=> 6
d.offset            #=> (7/48)
d.zone              #=> "+03:30"
d += Rational('1.5')
                    #=> #<DateTime: 2001-02-04%16:05:06+03:30 ...>
d = d.new_offset('+09:00')
                    #=> #<DateTime: 2001-02-04%21:35:06+09:00 ...>
d.strftime('%I:%M:%S %p')
                    #=> "09:35:06 PM"
d > DateTime.new(1999)
                    #=> trueWhen should you use DateTime and when should you use Time?
It's a common misconception that William Shakespeare and Miguel de Cervantes died on the same day in history - so much so that UNESCO named April 23 as World Book Day because of this fact. However, because England hadn't yet adopted the Gregorian Calendar Reform (and wouldn't until 1752) their deaths are actually 10 days apart. Since Ruby's ::Time class implements a proleptic Gregorian calendar and has no concept of calendar reform there's no way to express this with ::Time objects. This is where DateTime steps in:
shakespeare = DateTime.iso8601('1616-04-23', Date::ENGLAND)
 #=> Tue, 23 Apr 1616 00:00:00 +0000
cervantes = DateTime.iso8601('1616-04-23', Date::ITALY)
 #=> Sat, 23 Apr 1616 00:00:00 +0000Already you can see something is weird - the days of the week are different. Taking this further:
cervantes == shakespeare
 #=> false
(shakespeare - cervantes).to_i
 #=> 10This shows that in fact they died 10 days apart (in reality 11 days since Cervantes died a day earlier but was buried on the 23rd). We can see the actual date of Shakespeare's death by using the #gregorian method to convert it:
shakespeare.gregorian
 #=> Tue, 03 May 1616 00:00:00 +0000So there's an argument that all the celebrations that take place on the 23rd April in Stratford-upon-Avon are actually the wrong date since England is now using the Gregorian calendar. You can see why when we transition across the reform date boundary:
# start off with the anniversary of Shakespeare's birth in 1751
shakespeare = DateTime.iso8601('1751-04-23', Date::ENGLAND)
 #=> Tue, 23 Apr 1751 00:00:00 +0000
# add 366 days since 1752 is a leap year and April 23 is after February 29
shakespeare + 366
 #=> Thu, 23 Apr 1752 00:00:00 +0000
# add another 365 days to take us to the anniversary in 1753
shakespeare + 366 + 365
 #=> Fri, 04 May 1753 00:00:00 +0000As you can see, if we're accurately tracking the number of solar years since Shakespeare's birthday then the correct anniversary date would be the 4th May and not the 23rd April.
So when should you use DateTime in Ruby and when should you use Time? Almost certainly you'll want to use ::Time since your app is probably dealing with current dates and times. However, if you need to deal with dates and times in a historical context you'll want to use DateTime to avoid making the same mistakes as UNESCO. If you also have to deal with timezones then best of luck - just bear in mind that you'll probably be dealing with local solar times, since it wasn't until the 19th century that the introduction of the railways necessitated the need for Standard Time and eventually timezones.
Constant Summary
::Date - Inherited
ABBR_DAYNAMES, ABBR_MONTHNAMES, DAYNAMES, ENGLAND, GREGORIAN, ITALY, JULIAN, MONTHNAMES
Class Method Summary
- 
    
      ._strptime(string[, format='%FT%T%z'])  ⇒ Hash 
    
    Parses the given representation of date and time with the given template, and returns a hash of parsed elements. 
- 
    
      .civil([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
    
    Alias for .new. 
- 
    
      .commercial([cwyear=-4712[, cweek=1[, cwday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
    
    Creates a DateTimeobject denoting the given week date.
- 
    
      .httpdate(string='Mon, 01 Jan -4712 00:00:00 GMT'[, start=Date::ITALY])  ⇒ DateTime 
    
    Creates a new DateTimeobject by parsing from a string according to some RFC 2616 format.
- 
    
      .iso8601(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime 
    
    Creates a new DateTimeobject by parsing from a string according to some typical ISO 8601 formats.
- 
    
      .jd([jd=0[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]])  ⇒ DateTime 
    
    Creates a DateTimeobject denoting the given chronological Julian day number.
- 
    
      .jisx0301(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime 
    
    Creates a new DateTimeobject by parsing from a string according to some typical JIS X 0301 formats.
- 
    
      .new([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
      (also: .civil)
    
    constructor
    Creates a DateTimeobject denoting the given calendar date.
- 
    
      .now([start = Date::ITALY])  ⇒ DateTime 
    
    Creates a DateTimeobject denoting the present time.
- 
    
      .ordinal([year=-4712[, yday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]])  ⇒ DateTime 
    
    Creates a DateTimeobject denoting the given ordinal date.
- 
    
      .parse(string='-4712-01-01T00:00:00+00:00'[, comp=true[, start=Date::ITALY]])  ⇒ DateTime 
    
    Parses the given representation of date and time, and creates a DateTimeobject.
- 
    
      .rfc2822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
    
    Alias for .rfc822. 
- 
    
      .rfc3339(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime 
    
    Creates a new DateTimeobject by parsing from a string according to some typical RFC 3339 formats.
- 
    
      .rfc822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
      (also: .rfc2822)
    
    Creates a new DateTimeobject by parsing from a string according to some typical RFC 2822 formats.
- 
    
      .strptime([string='-4712-01-01T00:00:00+00:00'[, format='%FT%T%z'[ ,start=Date::ITALY]]])  ⇒ DateTime 
    
    Parses the given representation of date and time with the given template, and creates a DateTimeobject.
- 
    
      .xmlschema(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime 
    
    Creates a new DateTimeobject by parsing from a string according to some typical XML Schema formats.
::Date - Inherited
| ._httpdate | Returns a hash of parsed elements. | 
| ._iso8601 | Returns a hash of parsed elements. | 
| ._jisx0301 | Returns a hash of parsed elements. | 
| ._parse | Parses the given representation of date and time, and returns a hash of parsed elements. | 
| ._rfc2822 | Alias for Date._rfc822. | 
| ._rfc3339 | Returns a hash of parsed elements. | 
| ._rfc822 | Returns a hash of parsed elements. | 
| ._strptime | Parses the given representation of date and time with the given template, and returns a hash of parsed elements. | 
| ._xmlschema | Returns a hash of parsed elements. | 
| .civil | Alias for Date.new. | 
| .commercial | Creates a date object denoting the given week date. | 
| .gregorian_leap? | Alias for Date.leap?. | 
| .httpdate | Creates a new ::Date object by parsing from a string according to some RFC 2616 format. | 
| .iso8601 | Creates a new ::Date object by parsing from a string according to some typical ISO 8601 formats. | 
| .jd | Creates a date object denoting the given chronological Julian day number. | 
| .jisx0301 | Creates a new ::Date object by parsing from a string according to some typical JIS X 0301 formats. | 
| .julian_leap? | Returns true if the given year is a leap year of the proleptic Julian calendar. | 
| .leap? | Returns true if the given year is a leap year of the proleptic Gregorian calendar. | 
| .new | Creates a date object denoting the given calendar date. | 
| .ordinal | Creates a date object denoting the given ordinal date. | 
| .parse | Parses the given representation of date and time, and creates a date object. | 
| .rfc2822 | Alias for Date.rfc822. | 
| .rfc3339 | Creates a new ::Date object by parsing from a string according to some typical RFC 3339 formats. | 
| .rfc822 | Creates a new ::Date object by parsing from a string according to some typical RFC 2822 formats. | 
| .strptime | Parses the given representation of date and time with the given template, and creates a date object. | 
| .today | Creates a date object denoting the present day. | 
| .valid_civil? | Alias for Date.valid_date?. | 
| .valid_commercial? | Returns true if the given week date is valid, and false if not. | 
| .valid_date? | Returns true if the given calendar date is valid, and false if not. | 
| .valid_jd? | Just returns true. | 
| .valid_ordinal? | Returns true if the given ordinal date is valid, and false if not. | 
| .xmlschema | Creates a new ::Date object by parsing from a string according to some typical XML Schema formats. | 
| ._load | |
Instance Attribute Summary
::Date - Inherited
| #friday? | Returns true if the date is Friday. | 
| #gregorian | This method is equivalent to new_start(Date::GREGORIAN). | 
| #gregorian? | Returns true if the date is on or after the day of calendar reform. | 
| #julian | This method is equivalent to new_start(Date::JULIAN). | 
| #julian? | Returns true if the date is before the day of calendar reform. | 
| #leap? | Returns true if the year is a leap year. | 
| #monday? | Returns true if the date is Monday. | 
| #saturday? | Returns true if the date is Saturday. | 
| #sunday? | Returns true if the date is Sunday. | 
| #thursday? | Returns true if the date is Thursday. | 
| #tuesday? | Returns true if the date is Tuesday. | 
| #wednesday? | Returns true if the date is Wednesday. | 
Instance Method Summary
- 
    
      #iso8601([n = 0])  ⇒ String 
      (also: #xmlschema)
    
    This method is equivalent to strftime('%FT%T%:z'). 
- 
    
      #jisx0301([n = 0])  ⇒ String 
    
    Returns a string in a JIS X 0301 format. 
- 
    
      #rfc3339([n = 0])  ⇒ String 
    
    This method is equivalent to strftime('%FT%T%:z'). 
- 
    
      #strftime([format = '%FT%T%:z'])  ⇒ String 
    
    Formats date according to the directives in the given format string. 
- 
    
      #to_date  ⇒ date 
    
    Returns a ::Date object which denotes self. 
- 
    
      #to_datetime  ⇒ self 
    
    Returns self. 
- 
    
      #to_s  ⇒ String 
    
    Returns a string in an ISO 8601 format. 
- 
    
      #to_time  ⇒ Time 
    
    Returns a ::Time object which denotes self. 
- 
    
      #xmlschema([n = 0])  ⇒ String 
    
    Alias for #iso8601. 
::Date - Inherited
| #+ | Returns a date object pointing  | 
| #- | Returns the difference between the two dates if the other is a date object. | 
| #<< | Returns a date object pointing  | 
| #<=> | Compares the two dates and returns -1, zero, 1 or nil. | 
| #=== | Returns true if they are the same day. | 
| #>> | Returns a date object pointing  | 
| #ajd | Returns the astronomical Julian day number. | 
| #amjd | Returns the astronomical modified Julian day number. | 
| #asctime | Alias for Date#ctime. | 
| #ctime | Returns a string in asctime(3) format (but without “n0” at the end). | 
| #cwday | Returns the day of calendar week (1-7, Monday is 1). | 
| #cweek | Returns the calendar week number (1-53). | 
| #cwyear | Returns the calendar week based year. | 
| #day | Returns the day of the month (1-31). | 
| #day_fraction | Returns the fractional part of the day. | 
| #downto | This method is equivalent to step(min, -1){|date| …}. | 
| #england | This method is equivalent to new_start(Date::ENGLAND). | 
| #httpdate | This method is equivalent to strftime('%a, %d %b %Y %T GMT'). | 
| #inspect | Returns the value as a string for inspection. | 
| #iso8601 | This method is equivalent to strftime('%F'). | 
| #italy | This method is equivalent to new_start(Date::ITALY). | 
| #jd | Returns the Julian day number. | 
| #jisx0301 | Returns a string in a JIS X 0301 format. | 
| #ld | Returns the Lilian day number. | 
| #mday | Alias for Date#day. | 
| #mjd | Returns the modified Julian day number. | 
| #mon | Returns the month (1-12). | 
| #month | Alias for Date#mon. | 
| #new_start | Duplicates self and resets its day of calendar reform. | 
| #next | Returns a date object denoting the following day. | 
| #next_day | This method is equivalent to d + n. | 
| #next_month | This method is equivalent to d >> n. | 
| #next_year | This method is equivalent to d >> (n * 12). | 
| #prev_day | This method is equivalent to d - n. | 
| #prev_month | This method is equivalent to d << n. | 
| #prev_year | This method is equivalent to d << (n * 12). | 
| #rfc2822 | Alias for Date#rfc822. | 
| #rfc3339 | This method is equivalent to strftime('%FT%T%:z'). | 
| #rfc822 | This method is equivalent to strftime('%a, %-d %b %Y %T %z'). | 
| #start | Returns the Julian day number denoting the day of calendar reform. | 
| #step | Iterates evaluation of the given block, which takes a date object. | 
| #strftime | Formats date according to the directives in the given format string. | 
| #succ | Alias for Date#next. | 
| #to_date | Returns self. | 
| #to_datetime | Returns a  | 
| #to_s | Returns a string in an ISO 8601 format. | 
| #to_time | Returns a ::Time object which denotes self. | 
| #upto | This method is equivalent to step(max, 1){|date| …}. | 
| #wday | Returns the day of week (0-6, Sunday is zero). | 
| #xmlschema | Alias for Date#iso8601. | 
| #yday | Returns the day of the year (1-366). | 
| #year | Returns the year. | 
| #hour | Returns the hour (0-23). | 
| #min | Returns the minute (0-59). | 
| #minute | Alias for Date#min. | 
| #new_offset | Duplicates self and resets its offset. | 
| #offset | Returns the offset. | 
| #sec | Returns the second (0-59). | 
| #sec_fraction | Returns the fractional part of the second. | 
| #second | Alias for Date#sec. | 
| #second_fraction | Alias for Date#sec_fraction. | 
| #zone | Returns the timezone. | 
| #eql?, #hash, #initialize_copy, #marshal_dump, #marshal_load | |
Constructor Details
    
      .civil([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
      .new([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
    
    Also known as: .civil
  
DateTime 
      .new([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
    Creates a DateTime object denoting the given calendar date.
DateTime.new(2001,2,3)    #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...>
DateTime.new(2001,2,3,4,5,6,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.new(2001,-11,-26,-20,-55,-54,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 7355
static VALUE
datetime_s_civil(int argc, VALUE *argv, VALUE klass)
{
    VALUE vy, vm, vd, vh, vmin, vs, vof, vsg, y, fr, fr2, ret;
    int m, d, h, min, s, rof;
    double sg;
    rb_scan_args(argc, argv, "08", &vy, &vm, &vd, &vh, &vmin, &vs, &vof, &vsg);
    y = INT2FIX(-4712);
    m = 1;
    d = 1;
    h = min = s = 0;
    fr2 = INT2FIX(0);
    rof = 0;
    sg = DEFAULT_SG;
    switch (argc) {
      case 8:
	val2sg(vsg, sg);
      case 7:
	val2off(vof, rof);
      case 6:
	num2int_with_frac(s, positive_inf);
      case 5:
	num2int_with_frac(min, 5);
      case 4:
	num2int_with_frac(h, 4);
      case 3:
	num2int_with_frac(d, 3);
      case 2:
	m = NUM2INT(vm);
      case 1:
	y = vy;
    }
    if (guess_style(y, sg) < 0) {
	VALUE nth;
	int ry, rm, rd, rh, rmin, rs;
	if (!valid_gregorian_p(y, m, d,
			       &nth, &ry,
			       &rm, &rd))
	    rb_raise(rb_eArgError, "invalid date");
	if (!c_valid_time_p(h, min, s, &rh, &rmin, &rs))
	    rb_raise(rb_eArgError, "invalid date");
	canon24oc();
	ret = d_complex_new_internal(klass,
				     nth, 0,
				     0, INT2FIX(0),
				     rof, sg,
				     ry, rm, rd,
				     rh, rmin, rs,
				     HAVE_CIVIL | HAVE_TIME);
    }
    else {
	VALUE nth;
	int ry, rm, rd, rh, rmin, rs, rjd, rjd2, ns;
	if (!valid_civil_p(y, m, d, sg,
			   &nth, &ry,
			   &rm, &rd, &rjd,
			   &ns))
	    rb_raise(rb_eArgError, "invalid date");
	if (!c_valid_time_p(h, min, s, &rh, &rmin, &rs))
	    rb_raise(rb_eArgError, "invalid date");
	canon24oc();
	rjd2 = jd_local_to_utc(rjd,
			       time_to_df(rh, rmin, rs),
			       rof);
	ret = d_complex_new_internal(klass,
				     nth, rjd2,
				     0, INT2FIX(0),
				     rof, sg,
				     ry, rm, rd,
				     rh, rmin, rs,
				     HAVE_JD | HAVE_CIVIL | HAVE_TIME);
    }
    add_frac();
    return ret;
}
  Class Method Details
    ._strptime(string[, format='%FT%T%z'])  ⇒ Hash   
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.
See also strptime(3) and #strftime.
# File 'ext/date/date_core.c', line 7867
static VALUE
datetime_s__strptime(int argc, VALUE *argv, VALUE klass)
{
    return date_s__strptime_internal(argc, argv, klass, "%FT%T%z");
}
  
    
      .civil([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
      .new([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
    
  
DateTime 
      .new([year=-4712[, month=1[, mday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime 
    Alias for .new.
    .commercial([cwyear=-4712[, cweek=1[, cwday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]]])  ⇒ DateTime   
Creates a DateTime object denoting the given week date.
DateTime.commercial(2001) #=> #<DateTime: 2001-01-01T00:00:00+00:00 ...>
DateTime.commercial(2002) #=> #<DateTime: 2001-12-31T00:00:00+00:00 ...>
DateTime.commercial(2001,5,6,4,5,6,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 7452
static VALUE
datetime_s_commercial(int argc, VALUE *argv, VALUE klass)
{
    VALUE vy, vw, vd, vh, vmin, vs, vof, vsg, y, fr, fr2, ret;
    int w, d, h, min, s, rof;
    double sg;
    rb_scan_args(argc, argv, "08", &vy, &vw, &vd, &vh, &vmin, &vs, &vof, &vsg);
    y = INT2FIX(-4712);
    w = 1;
    d = 1;
    h = min = s = 0;
    fr2 = INT2FIX(0);
    rof = 0;
    sg = DEFAULT_SG;
    switch (argc) {
      case 8:
	val2sg(vsg, sg);
      case 7:
	val2off(vof, rof);
      case 6:
	num2int_with_frac(s, positive_inf);
      case 5:
	num2int_with_frac(min, 5);
      case 4:
	num2int_with_frac(h, 4);
      case 3:
	num2int_with_frac(d, 3);
      case 2:
	w = NUM2INT(vw);
      case 1:
	y = vy;
    }
    {
	VALUE nth;
	int ry, rw, rd, rh, rmin, rs, rjd, rjd2, ns;
	if (!valid_commercial_p(y, w, d, sg,
				&nth, &ry,
				&rw, &rd, &rjd,
				&ns))
	    rb_raise(rb_eArgError, "invalid date");
	if (!c_valid_time_p(h, min, s, &rh, &rmin, &rs))
	    rb_raise(rb_eArgError, "invalid date");
	canon24oc();
	rjd2 = jd_local_to_utc(rjd,
			       time_to_df(rh, rmin, rs),
			       rof);
	ret = d_complex_new_internal(klass,
				     nth, rjd2,
				     0, INT2FIX(0),
				     rof, sg,
				     0, 0, 0,
				     rh, rmin, rs,
				     HAVE_JD | HAVE_TIME);
    }
    add_frac();
    return ret;
}
  
    .httpdate(string='Mon, 01 Jan -4712 00:00:00 GMT'[, start=Date::ITALY])  ⇒ DateTime   
Creates a new DateTime object by parsing from a string according to some RFC 2616 format.
DateTime.httpdate('Sat, 03 Feb 2001 04:05:06 GMT')
                          #=> #<DateTime: 2001-02-03T04:05:06+00:00 ...># File 'ext/date/date_core.c', line 8104
static VALUE
datetime_s_httpdate(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, sg;
    rb_scan_args(argc, argv, "02", &str, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("Mon, 01 Jan -4712 00:00:00 GMT");
      case 1:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE hash = date_s__httpdate(klass, str);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    .iso8601(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime   
Creates a new DateTime object by parsing from a string according to some typical ISO 8601 formats.
DateTime.iso8601('2001-02-03T04:05:06+07:00')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.iso8601('20010203T040506+0700')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.iso8601('2001-W05-6T04:05:06+07:00')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 7983
static VALUE
datetime_s_iso8601(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, sg;
    rb_scan_args(argc, argv, "02", &str, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
      case 1:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE hash = date_s__iso8601(klass, str);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    .jd([jd=0[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]])  ⇒ DateTime   
Creates a DateTime object denoting the given chronological Julian day number.
DateTime.jd(2451944)      #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...>
DateTime.jd(2451945)      #=> #<DateTime: 2001-02-04T00:00:00+00:00 ...>
DateTime.jd(Rational('0.5'))
                          #=> #<DateTime: -4712-01-01T12:00:00+00:00 ...># File 'ext/date/date_core.c', line 7211
static VALUE
datetime_s_jd(int argc, VALUE *argv, VALUE klass)
{
    VALUE vjd, vh, vmin, vs, vof, vsg, jd, fr, fr2, ret;
    int h, min, s, rof;
    double sg;
    rb_scan_args(argc, argv, "06", &vjd, &vh, &vmin, &vs, &vof, &vsg);
    jd = INT2FIX(0);
    h = min = s = 0;
    fr2 = INT2FIX(0);
    rof = 0;
    sg = DEFAULT_SG;
    switch (argc) {
      case 6:
	val2sg(vsg, sg);
      case 5:
	val2off(vof, rof);
      case 4:
	num2int_with_frac(s, positive_inf);
      case 3:
	num2int_with_frac(min, 3);
      case 2:
	num2int_with_frac(h, 2);
      case 1:
	num2num_with_frac(jd, 1);
    }
    {
	VALUE nth;
	int rh, rmin, rs, rjd, rjd2;
	if (!c_valid_time_p(h, min, s, &rh, &rmin, &rs))
	    rb_raise(rb_eArgError, "invalid date");
	canon24oc();
	decode_jd(jd, &nth, &rjd);
	rjd2 = jd_local_to_utc(rjd,
			       time_to_df(rh, rmin, rs),
			       rof);
	ret = d_complex_new_internal(klass,
				     nth, rjd2,
				     0, INT2FIX(0),
				     rof, sg,
				     0, 0, 0,
				     rh, rmin, rs,
				     HAVE_JD | HAVE_TIME);
    }
    add_frac();
    return ret;
}
  
    .jisx0301(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime   
Creates a new DateTime object by parsing from a string according to some typical JIS X 0301 formats.
DateTime.jisx0301('H13.02.03T04:05:06+07:00')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 8134
static VALUE
datetime_s_jisx0301(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, sg;
    rb_scan_args(argc, argv, "02", &str, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
      case 1:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE hash = date_s__jisx0301(klass, str);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    .now([start = Date::ITALY])  ⇒ DateTime   
Creates a DateTime object denoting the present time.
DateTime.now              #=> #<DateTime: 2011-06-11T21:20:44+09:00 ...># File 'ext/date/date_core.c', line 7666
static VALUE
datetime_s_now(int argc, VALUE *argv, VALUE klass)
{
    VALUE vsg, nth, ret;
    double sg;
#ifdef HAVE_CLOCK_GETTIME
    struct timespec ts;
#else
    struct timeval tv;
#endif
    time_t sec;
    struct tm tm;
    long sf, of;
    int y, ry, m, d, h, min, s;
    rb_scan_args(argc, argv, "01", &vsg);
    if (argc < 1)
	sg = DEFAULT_SG;
    else
	sg = NUM2DBL(vsg);
#ifdef HAVE_CLOCK_GETTIME
    if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
	rb_sys_fail("clock_gettime");
    sec = ts.tv_sec;
#else
    if (gettimeofday(&tv, NULL) == -1)
	rb_sys_fail("gettimeofday");
    sec = tv.tv_sec;
#endif
    tzset();
    if (!localtime_r(&sec, &tm))
	rb_sys_fail("localtime");
    y = tm.tm_year + 1900;
    m = tm.tm_mon + 1;
    d = tm.tm_mday;
    h = tm.tm_hour;
    min = tm.tm_min;
    s = tm.tm_sec;
    if (s == 60)
	s = 59;
#ifdef HAVE_STRUCT_TM_TM_GMTOFF
    of = tm.tm_gmtoff;
#elif defined(HAVE_TIMEZONE)
#ifdef HAVE_ALTZONE
    of = (long)-((tm.tm_isdst > 0) ? altzone : timezone);
#else
    of = (long)-timezone;
    if (tm.tm_isdst) {
	time_t sec2;
	tm.tm_isdst = 0;
	sec2 = mktime(&tm);
	of += (long)difftime(sec2, sec);
    }
#endif
#elif defined(HAVE_TIMEGM)
    {
	time_t sec2;
	sec2 = timegm(&tm);
	of = (long)difftime(sec2, sec);
    }
#else
    {
	struct tm tm2;
	time_t sec2;
	if (!gmtime_r(&sec, &tm2))
	    rb_sys_fail("gmtime");
	tm2.tm_isdst = tm.tm_isdst;
	sec2 = mktime(&tm2);
	of = (long)difftime(sec, sec2);
    }
#endif
#ifdef HAVE_CLOCK_GETTIME
    sf = ts.tv_nsec;
#else
    sf = tv.tv_usec * 1000;
#endif
    if (of < -DAY_IN_SECONDS || of > DAY_IN_SECONDS) {
	of = 0;
	rb_warning("invalid offset is ignored");
    }
    decode_year(INT2FIX(y), -1, &nth, &ry);
    ret = d_complex_new_internal(klass,
				 nth, 0,
				 0, LONG2NUM(sf),
				 (int)of, GREGORIAN,
				 ry, m, d,
				 h, min, s,
				 HAVE_CIVIL | HAVE_TIME);
    {
	get_d1(ret);
	set_sg(dat, sg);
    }
    return ret;
}
  
    .ordinal([year=-4712[, yday=1[, hour=0[, minute=0[, second=0[, offset=0[, start=Date::ITALY]]]]]]])  ⇒ DateTime   
Creates a DateTime object denoting the given ordinal date.
DateTime.ordinal(2001,34) #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...>
DateTime.ordinal(2001,34,4,5,6,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.ordinal(2001,-332,-20,-55,-54,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 7279
static VALUE
datetime_s_ordinal(int argc, VALUE *argv, VALUE klass)
{
    VALUE vy, vd, vh, vmin, vs, vof, vsg, y, fr, fr2, ret;
    int d, h, min, s, rof;
    double sg;
    rb_scan_args(argc, argv, "07", &vy, &vd, &vh, &vmin, &vs, &vof, &vsg);
    y = INT2FIX(-4712);
    d = 1;
    h = min = s = 0;
    fr2 = INT2FIX(0);
    rof = 0;
    sg = DEFAULT_SG;
    switch (argc) {
      case 7:
	val2sg(vsg, sg);
      case 6:
	val2off(vof, rof);
      case 5:
	num2int_with_frac(s, positive_inf);
      case 4:
	num2int_with_frac(min, 4);
      case 3:
	num2int_with_frac(h, 3);
      case 2:
	num2int_with_frac(d, 2);
      case 1:
	y = vy;
    }
    {
	VALUE nth;
	int ry, rd, rh, rmin, rs, rjd, rjd2, ns;
	if (!valid_ordinal_p(y, d, sg,
			     &nth, &ry,
			     &rd, &rjd,
			     &ns))
	    rb_raise(rb_eArgError, "invalid date");
	if (!c_valid_time_p(h, min, s, &rh, &rmin, &rs))
	    rb_raise(rb_eArgError, "invalid date");
	canon24oc();
	rjd2 = jd_local_to_utc(rjd,
			       time_to_df(rh, rmin, rs),
			       rof);
	ret = d_complex_new_internal(klass,
				     nth, rjd2,
				     0, INT2FIX(0),
				     rof, sg,
				     0, 0, 0,
				     rh, rmin, rs,
				     HAVE_JD | HAVE_TIME);
    }
    add_frac();
    return ret;
}
  
    .parse(string='-4712-01-01T00:00:00+00:00'[, comp=true[, start=Date::ITALY]])  ⇒ DateTime   
Parses the given representation of date and time, and creates a DateTime 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”, makes it full.
DateTime.parse('2001-02-03T04:05:06+07:00')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.parse('20010203T040506+0700')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.parse('3rd Feb 2001 04:05:06 PM')
                          #=> #<DateTime: 2001-02-03T16:05:06+00:00 ...># File 'ext/date/date_core.c', line 7943
static VALUE
datetime_s_parse(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, comp, sg;
    rb_scan_args(argc, argv, "03", &str, &comp, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
      case 1:
	comp = Qtrue;
      case 2:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE argv2[2], hash;
	argv2[0] = str;
	argv2[1] = comp;
	hash = date_s__parse(2, argv2, klass);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    
      .rfc2822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
      .rfc822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
    
  
DateTime 
      .rfc822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
    Alias for .rfc822.
    .rfc3339(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime   
Creates a new DateTime object by parsing from a string according to some typical RFC 3339 formats.
DateTime.rfc3339('2001-02-03T04:05:06+07:00')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 8013
static VALUE
datetime_s_rfc3339(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, sg;
    rb_scan_args(argc, argv, "02", &str, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
      case 1:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE hash = date_s__rfc3339(klass, str);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    
      .rfc2822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
      .rfc822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
    
    Also known as: .rfc2822
  
DateTime 
      .rfc822(string='Mon, 1 Jan -4712 00:00:00 +0000'[, start=Date::ITALY])  ⇒ DateTime 
    Creates a new DateTime object by parsing from a string according to some typical RFC 2822 formats.
DateTime.rfc2822('Sat, 3 Feb 2001 04:05:06 +0700')
                         #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 8074
static VALUE
datetime_s_rfc2822(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, sg;
    rb_scan_args(argc, argv, "02", &str, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("Mon, 1 Jan -4712 00:00:00 +0000");
      case 1:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE hash = date_s__rfc2822(klass, str);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    .strptime([string='-4712-01-01T00:00:00+00:00'[, format='%FT%T%z'[ ,start=Date::ITALY]]])  ⇒ DateTime   
Parses the given representation of date and time with the given template, and creates a DateTime object.  strptime does not support specification of flags and width unlike strftime.
DateTime.strptime('2001-02-03T04:05:06+07:00', '%Y-%m-%dT%H:%M:%S%z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('03-02-2001 04:05:06 PM', '%d-%m-%Y %I:%M:%S %p')
                          #=> #<DateTime: 2001-02-03T16:05:06+00:00 ...>
DateTime.strptime('2001-W05-6T04:05:06+07:00', '%G-W%V-%uT%H:%M:%S%z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('2001 04 6 04 05 06 +7', '%Y %U %w %H %M %S %z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('2001 05 6 04 05 06 +7', '%Y %W %u %H %M %S %z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('-1', '%s')
                          #=> #<DateTime: 1969-12-31T23:59:59+00:00 ...>
DateTime.strptime('-1000', '%Q')
                          #=> #<DateTime: 1969-12-31T23:59:59+00:00 ...>
DateTime.strptime('sat3feb014pm+7', '%a%d%b%y%H%p%z')
                          #=> #<DateTime: 2001-02-03T16:00:00+07:00 ...>See also strptime(3) and #strftime.
# File 'ext/date/date_core.c', line 7900
static VALUE
datetime_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("-4712-01-01T00:00:00+00:00");
      case 1:
	fmt = rb_str_new2("%FT%T%z");
      case 2:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE argv2[2], hash;
	argv2[0] = str;
	argv2[1] = fmt;
	hash = date_s__strptime(2, argv2, klass);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  
    .xmlschema(string='-4712-01-01T00:00:00+00:00'[, start=Date::ITALY])  ⇒ DateTime   
Creates a new DateTime object by parsing from a string according to some typical XML Schema formats.
DateTime.xmlschema('2001-02-03T04:05:06+07:00')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...># File 'ext/date/date_core.c', line 8043
static VALUE
datetime_s_xmlschema(int argc, VALUE *argv, VALUE klass)
{
    VALUE str, sg;
    rb_scan_args(argc, argv, "02", &str, &sg);
    switch (argc) {
      case 0:
	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
      case 1:
	sg = INT2FIX(DEFAULT_SG);
    }
    {
	VALUE hash = date_s__xmlschema(klass, str);
	return dt_new_by_frags(klass, hash, sg);
    }
}
  Instance Method Details
    
      #iso8601([n = 0])  ⇒ String 
      #xmlschema([n = 0])  ⇒ String 
    
    Also known as: #xmlschema
  
String 
      #xmlschema([n = 0])  ⇒ String 
    # File 'ext/date/date_core.c', line 8382
static VALUE
dt_lite_iso8601(int argc, VALUE *argv, VALUE self)
{
    long n = 0;
    rb_check_arity(argc, 0, 1);
    if (argc >= 1)
	n = NUM2LONG(argv[0]);
    return rb_str_append(strftimev("%Y-%m-%d", self, set_tmx),
			 iso8601_timediv(self, n));
}
  
    #jisx0301([n = 0])  ⇒ String   
# File 'ext/date/date_core.c', line 8421
static VALUE
dt_lite_jisx0301(int argc, VALUE *argv, VALUE self)
{
    long n = 0;
    rb_check_arity(argc, 0, 1);
    if (argc >= 1)
	n = NUM2LONG(argv[0]);
    return rb_str_append(d_lite_jisx0301(self),
			 iso8601_timediv(self, n));
}
  
    #rfc3339([n = 0])  ⇒ String   
# File 'ext/date/date_core.c', line 8405
static VALUE
dt_lite_rfc3339(int argc, VALUE *argv, VALUE self)
{
    return dt_lite_iso8601(argc, argv, self);
}
  
    #strftime([format = '%FT%T%:z'])  ⇒ String   
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.
:  use colons for %z.The minimum field width specifies the minimum width.
The modifiers are “E” and “O”. They are ignored.
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..59)
  %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.
# File 'ext/date/date_core.c', line 8348
static VALUE
dt_lite_strftime(int argc, VALUE *argv, VALUE self)
{
    return date_strftime_internal(argc, argv, self,
				  "%Y-%m-%dT%H:%M:%S%:z", set_tmx);
}
  
    #to_date  ⇒ date   
Returns a ::Date object which denotes self.
# File 'ext/date/date_core.c', line 8628
static VALUE
datetime_to_date(VALUE self)
{
    get_d1a(self);
    if (simple_dat_p(adat)) {
	VALUE new = d_lite_s_alloc_simple(cDate);
	{
	    get_d1b(new);
	    bdat->s = adat->s;
	    bdat->s.jd = m_local_jd(adat);
	    return new;
	}
    }
    else {
	VALUE new = d_lite_s_alloc_simple(cDate);
	{
	    get_d1b(new);
	    copy_complex_to_simple(new, &bdat->s, &adat->c)
	    bdat->s.jd = m_local_jd(adat);
	    bdat->s.flags &= ~(HAVE_DF | HAVE_TIME | COMPLEX_DAT);
	    return new;
	}
    }
}
  
    #to_datetime  ⇒ self   
Returns self.
# File 'ext/date/date_core.c', line 8660
static VALUE
datetime_to_datetime(VALUE self)
{
    return self;
}
  
    #to_s  ⇒ String   
Returns a string in an ISO 8601 format. (This method doesn't use the expanded representations.)
DateTime.new(2001,2,3,4,5,6,'-7').to_s
                         #=> "2001-02-03T04:05:06-07:00"# File 'ext/date/date_core.c', line 8164
static VALUE
dt_lite_to_s(VALUE self)
{
    return strftimev("%Y-%m-%dT%H:%M:%S%:z", self, set_tmx);
}
  #to_time ⇒ Time
Returns a ::Time object which denotes self.
# File 'ext/date/date_core.c', line 8598
static VALUE
datetime_to_time(VALUE self)
{
    volatile VALUE dup = dup_obj(self);
    {
	VALUE t;
	get_d1(dup);
	t = rb_funcall(rb_cTime,
		   rb_intern("new"),
                   7,
		   m_real_year(dat),
		   INT2FIX(m_mon(dat)),
		   INT2FIX(m_mday(dat)),
		   INT2FIX(m_hour(dat)),
		   INT2FIX(m_min(dat)),
		   f_add(INT2FIX(m_sec(dat)),
			 m_sf_in_sec(dat)),
		   INT2FIX(m_of(dat)));
	return t;
    }
}
  
    
      #iso8601([n = 0])  ⇒ String 
      #xmlschema([n = 0])  ⇒ String 
    
  
String 
      #xmlschema([n = 0])  ⇒ String 
    Alias for #iso8601.