Class representing a date and time.
See the documentation to the file date.rb for an overview.
DateTime objects are immutable once created.
The following methods are defined in Date, but declared private there. They are made public in DateTime. They are documented here.
Get the hour-of-the-day of the time. This is given using the 24-hour clock, counting from midnight. The first hour after midnight is hour 0; the last hour of the day is hour 23.
Get the minute-of-the-hour of the time.
Get the second-of-the-minute of the time.
Get the fraction of a second of the time. This is returned as a
Rational
. The unit is in days. I do NOT recommend you to use
this method.
Get the time zone as a String. This is representation of the time offset such as “+1000”, not the true time-zone name.
Get the time zone offset as a fraction of a day. This is returned as a
Rational
.
Create a new DateTime object, identical to the
current one, except with a new time zone offset of of
.
of
is the new offset from UTC as a fraction of a day.
# File date/format.rb, line 1060 def self._strptime(str, fmt='%FT%T%z') super(str, fmt) end
Create a new DateTime object corresponding to
the specified Civil Date and hour h
,
minute min
, second s
.
The 24-hour clock is used. Negative values of h
,
min
, and sec
are treating as counting backwards
from the end of the next larger unit (e.g. a min
of -2 is
treated as 58). No wraparound is performed. If an invalid time portion is
specified, an ArgumentError is raised.
of
is the offset from UTC as a fraction of a day (defaults to
0). sg
specifies the Day of Calendar Reform.
y
defaults to -4712, m
to 1, and d
to 1; this is Julian Day Number day 0. The time values default to 0.
# File date.rb, line 1483 def self.civil(y=-4712, m=1, d=1, h=0, min=0, s=0, of=0, sg=ITALY) unless (jd = valid_civil?(y, m, d, sg)) && (fr = valid_time?(h, min, s)) raise ArgumentError, 'invalid date' end if String === of of = (zone_to_diff(of) || 0).to_r/86400 end new!(jd_to_ajd(jd, fr, of), of, sg) end
Create a new DateTime object corresponding to
the specified Commercial Date and hour
h
, minute min
, second s
.
The 24-hour clock is used. Negative values of h
,
min
, and sec
are treating as counting backwards
from the end of the next larger unit (e.g. a min
of -2 is
treated as 58). No wraparound is performed. If an invalid time portion is
specified, an ArgumentError is raised.
of
is the offset from UTC as a fraction of a day (defaults to
0). sg
specifies the Day of Calendar Reform.
y
defaults to 1582, w
to 41, and d
to 5; this is the Day of Calendar Reform for Italy and the Catholic
countries. The time values default to 0.
# File date.rb, line 1511 def self.commercial(y=1582, w=41, d=5, h=0, min=0, s=0, of=0, sg=ITALY) unless (jd = valid_commercial?(y, w, d, sg)) && (fr = valid_time?(h, min, s)) raise ArgumentError, 'invalid date' end if String === of of = (zone_to_diff(of) || 0).to_r/86400 end new!(jd_to_ajd(jd, fr, of), of, sg) end
Create a new DateTime object corresponding to
the specified Julian Day Number jd
and hour h
,
minute min
, second s
.
The 24-hour clock is used. Negative values of h
,
min
, and sec
are treating as counting backwards
from the end of the next larger unit (e.g. a min
of -2 is
treated as 58). No wraparound is performed. If an invalid time portion is
specified, an ArgumentError is raised.
of
is the offset from UTC as a fraction of a day (defaults to
0). sg
specifies the Day of Calendar Reform.
All day/time values default to 0.
# File date.rb, line 1433 def self.jd(jd=0, h=0, min=0, s=0, of=0, sg=ITALY) unless (jd = valid_jd?(jd, sg)) && (fr = valid_time?(h, min, s)) raise ArgumentError, 'invalid date' end if String === of of = (zone_to_diff(of) || 0).to_r/86400 end new!(jd_to_ajd(jd, fr, of), of, sg) end
Create a new DateTime object representing the current time.
sg
specifies the Day of Calendar Reform.
# File date.rb, line 1635 def self.now(sg=ITALY) t = Time.now jd = civil_to_jd(t.year, t.mon, t.mday, sg) fr = time_to_day_fraction(t.hour, t.min, [t.sec, 59].min) + Rational(t.usec, 86400_000_000) of = Rational(t.utc_offset, 86400) new!(jd_to_ajd(jd, fr, of), of, sg) end
Create a new DateTime object corresponding to
the specified Ordinal Date and hour h
,
minute min
, second s
.
The 24-hour clock is used. Negative values of h
,
min
, and sec
are treating as counting backwards
from the end of the next larger unit (e.g. a min
of -2 is
treated as 58). No wraparound is performed. If an invalid time portion is
specified, an ArgumentError is raised.
of
is the offset from UTC as a fraction of a day (defaults to
0). sg
specifies the Day of Calendar Reform.
y
defaults to -4712, and d
to 1; this is Julian
Day Number day 0. The time values default to 0.
# File date.rb, line 1458 def self.ordinal(y=-4712, d=1, h=0, min=0, s=0, of=0, sg=ITALY) unless (jd = valid_ordinal?(y, d, sg)) && (fr = valid_time?(h, min, s)) raise ArgumentError, 'invalid date' end if String === of of = (zone_to_diff(of) || 0).to_r/86400 end new!(jd_to_ajd(jd, fr, of), of, sg) end
Create a new DateTime object by parsing from a String, without specifying the format.
str
is a String holding a date-time representation.
comp
specifies whether to interpret 2-digit years as 19XX
(>= 69) or 20XX (< 69); the default is not to. The method will
attempt to parse a date-time from the String using various heuristics; see
#_parse in date/format.rb for more details. If parsing fails, an
ArgumentError will be raised.
The default str
is '-4712-01-01T00:00:00+00:00'; this
is Julian Day Number day 0.
sg
specifies the Day of Calendar Reform.
# File date.rb, line 1585 def self.parse(str='-4712-01-01T00:00:00+00:00', comp=false, sg=ITALY) elem = _parse(str, comp) new_by_frags(elem, sg) end
Create a new DateTime object by parsing from a String according to a specified format.
str
is a String holding a date-time representation.
fmt
is the format that the date-time is in. See
date/format.rb for details on supported formats.
The default str
is '-4712-01-01T00:00:00+00:00', and
the default fmt
is '%FT%T%z'. This gives midnight on
Julian Day Number day 0.
sg
specifies the Day of Calendar Reform.
An ArgumentError will be raised if str
cannot be parsed.
# File date.rb, line 1565 def self.strptime(str='-4712-01-01T00:00:00+00:00', fmt='%FT%T%z', sg=ITALY) elem = _strptime(str, fmt) new_by_frags(elem, sg) end