class DateTime
Public Class Methods
Returns DateTime
with local offset for given year if format is local else offset is zero.
DateTime.civil_from_format :local, 2012 # => Sun, 01 Jan 2012 00:00:00 +0300 DateTime.civil_from_format :local, 2012, 12, 17 # => Mon, 17 Dec 2012 00:00:00 +0000
# File lib/active_support/core_ext/date_time/conversions.rb, line 69 def self.civil_from_format(utc_or_local, year, month = 1, day = 1, hour = 0, min = 0, sec = 0) if utc_or_local.to_sym == :local offset = ::Time.local(year, month, day).utc_offset.to_r / 86400 else offset = 0 end civil(year, month, day, hour, min, sec, offset) end
Returns Time.zone.now.to_datetime
when Time.zone
or config.time_zone
are set, otherwise returns Time.now.to_datetime
.
# File lib/active_support/core_ext/date_time/calculations.rb, line 10 def current ::Time.zone ? ::Time.zone.now.to_datetime : ::Time.now.to_datetime end
Public Instance Methods
Layers additional behavior on DateTime#<=> so that Time
and ActiveSupport::TimeWithZone
instances can be compared with a DateTime
.
# File lib/active_support/core_ext/date_time/calculations.rb, line 204 def <=>(other) if other.respond_to? :to_datetime super other.to_datetime rescue nil else super end end
Duck-types as a Date-like class. See Object#acts_like?
.
# File lib/active_support/core_ext/date_time/acts_like.rb, line 8 def acts_like_date? true end
Duck-types as a Time-like class. See Object#acts_like?
.
# File lib/active_support/core_ext/date_time/acts_like.rb, line 13 def acts_like_time? true end
Uses Date
to provide precise Time
calculations for years, months, and days. The options
parameter takes a hash with any of these keys: :years
, :months
, :weeks
, :days
, :hours
, :minutes
, :seconds
.
# File lib/active_support/core_ext/date_time/calculations.rb, line 78 def advance(options) unless options[:weeks].nil? options[:weeks], partial_weeks = options[:weeks].divmod(1) options[:days] = options.fetch(:days, 0) + 7 * partial_weeks end unless options[:days].nil? options[:days], partial_days = options[:days].divmod(1) options[:hours] = options.fetch(:hours, 0) + 24 * partial_days end d = to_date.advance(options) datetime_advanced_by_date = change(year: d.year, month: d.month, day: d.day) seconds_to_advance = \ options.fetch(:seconds, 0) + options.fetch(:minutes, 0) * 60 + options.fetch(:hours, 0) * 3600 if seconds_to_advance.zero? datetime_advanced_by_date else datetime_advanced_by_date.since(seconds_to_advance) end end
Returns a new DateTime
representing the time a number of seconds ago. Do not use this method in combination with x.months, use months_ago instead!
# File lib/active_support/core_ext/date_time/calculations.rb, line 105 def ago(seconds) since(-seconds) end
Returns a new DateTime
representing the start of the day (0:00).
# File lib/active_support/core_ext/date_time/calculations.rb, line 118 def beginning_of_day change(hour: 0) end
Returns a new DateTime
representing the start of the hour (hh:00:00).
# File lib/active_support/core_ext/date_time/calculations.rb, line 142 def beginning_of_hour change(min: 0) end
Returns a new DateTime
representing the start of the minute (hh:mm:00).
# File lib/active_support/core_ext/date_time/calculations.rb, line 154 def beginning_of_minute change(sec: 0) end
Returns a new DateTime
where one or more of the elements have been changed according to the options
parameter. The time options (:hour
, :min
, :sec
) reset cascadingly, so if only the hour is passed, then minute and sec is set to 0. If the hour and minute is passed, then sec is set to 0. The options
parameter takes a hash with any of these keys: :year
, :month
, :day
, :hour
, :min
, :sec
, :offset
, :start
.
DateTime.new(2012, 8, 29, 22, 35, 0).change(day: 1) # => DateTime.new(2012, 8, 1, 22, 35, 0) DateTime.new(2012, 8, 29, 22, 35, 0).change(year: 1981, day: 1) # => DateTime.new(1981, 8, 1, 22, 35, 0) DateTime.new(2012, 8, 29, 22, 35, 0).change(year: 1981, hour: 0) # => DateTime.new(1981, 8, 29, 0, 0, 0)
# File lib/active_support/core_ext/date_time/calculations.rb, line 51 def change(options) if new_nsec = options[:nsec] raise ArgumentError, "Can't change both :nsec and :usec at the same time: #{options.inspect}" if options[:usec] new_fraction = Rational(new_nsec, 1000000000) else new_usec = options.fetch(:usec, (options[:hour] || options[:min] || options[:sec]) ? 0 : Rational(nsec, 1000)) new_fraction = Rational(new_usec, 1000000) end raise ArgumentError, "argument out of range" if new_fraction >= 1 ::DateTime.civil( options.fetch(:year, year), options.fetch(:month, month), options.fetch(:day, day), options.fetch(:hour, hour), options.fetch(:min, options[:hour] ? 0 : min), options.fetch(:sec, (options[:hour] || options[:min]) ? 0 : sec) + new_fraction, options.fetch(:offset, offset), options.fetch(:start, start) ) end
Returns a new DateTime
representing the end of the day (23:59:59).
# File lib/active_support/core_ext/date_time/calculations.rb, line 136 def end_of_day change(hour: 23, min: 59, sec: 59, usec: Rational(999999999, 1000)) end
Returns a new DateTime
representing the end of the hour (hh:59:59).
# File lib/active_support/core_ext/date_time/calculations.rb, line 148 def end_of_hour change(min: 59, sec: 59, usec: Rational(999999999, 1000)) end
Returns a new DateTime
representing the end of the minute (hh:mm:59).
# File lib/active_support/core_ext/date_time/calculations.rb, line 160 def end_of_minute change(sec: 59, usec: Rational(999999999, 1000)) end
Returns a formatted string of the offset from UTC, or an alternative string if the time zone is already UTC.
datetime = DateTime.civil(2000, 1, 1, 0, 0, 0, Rational(-6, 24)) datetime.formatted_offset # => "-06:00" datetime.formatted_offset(false) # => "-0600"
# File lib/active_support/core_ext/date_time/conversions.rb, line 51 def formatted_offset(colon = true, alternate_utc_string = nil) utc? && alternate_utc_string || ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, colon) end
Returns a Time
instance of the simultaneous time in the system timezone.
# File lib/active_support/core_ext/date_time/calculations.rb, line 166 def localtime(utc_offset = nil) utc = new_offset(0) Time.utc( utc.year, utc.month, utc.day, utc.hour, utc.min, utc.sec + utc.sec_fraction ).getlocal(utc_offset) end
Returns a new DateTime
representing the middle of the day (12:00)
# File lib/active_support/core_ext/date_time/calculations.rb, line 126 def middle_of_day change(hour: 12) end
Returns the fraction of a second as nanoseconds
# File lib/active_support/core_ext/date_time/conversions.rb, line 94 def nsec (sec_fraction * 1_000_000_000).to_i end
Overrides the default inspect method with a human readable one, e.g., “Mon, 21 Feb 2005 14:30:00 +0000”.
# File lib/active_support/core_ext/date_time/conversions.rb, line 56 def readable_inspect to_s(:rfc822) end
Returns the number of seconds since 00:00:00.
DateTime.new(2012, 8, 29, 0, 0, 0).seconds_since_midnight # => 0 DateTime.new(2012, 8, 29, 12, 34, 56).seconds_since_midnight # => 45296 DateTime.new(2012, 8, 29, 23, 59, 59).seconds_since_midnight # => 86399
# File lib/active_support/core_ext/date_time/calculations.rb, line 20 def seconds_since_midnight sec + (min * 60) + (hour * 3600) end
Returns the number of seconds until 23:59:59.
DateTime.new(2012, 8, 29, 0, 0, 0).seconds_until_end_of_day # => 86399 DateTime.new(2012, 8, 29, 12, 34, 56).seconds_until_end_of_day # => 41103 DateTime.new(2012, 8, 29, 23, 59, 59).seconds_until_end_of_day # => 0
# File lib/active_support/core_ext/date_time/calculations.rb, line 29 def seconds_until_end_of_day end_of_day.to_i - to_i end
Returns a new DateTime
representing the time a number of seconds since the instance time. Do not use this method in combination with x.months, use months_since instead!
# File lib/active_support/core_ext/date_time/calculations.rb, line 112 def since(seconds) self + Rational(seconds, 86400) end
Returns the fraction of a second as a Rational
DateTime.new(2012, 8, 29, 0, 0, 0.5).subsec # => (1/2)
# File lib/active_support/core_ext/date_time/calculations.rb, line 36 def subsec sec_fraction end
Converts self
to a floating-point number of seconds, including fractional microseconds, since the Unix epoch.
# File lib/active_support/core_ext/date_time/conversions.rb, line 79 def to_f seconds_since_unix_epoch.to_f + sec_fraction end
Convert to a formatted string. See Time::DATE_FORMATS for predefined formats.
This method is aliased to to_s
.
Examples¶ ↑
datetime = DateTime.civil(2007, 12, 4, 0, 0, 0, 0) # => Tue, 04 Dec 2007 00:00:00 +0000 datetime.to_formatted_s(:db) # => "2007-12-04 00:00:00" datetime.to_s(:db) # => "2007-12-04 00:00:00" datetime.to_s(:number) # => "20071204000000" datetime.to_formatted_s(:short) # => "04 Dec 00:00" datetime.to_formatted_s(:long) # => "December 04, 2007 00:00" datetime.to_formatted_s(:long_ordinal) # => "December 4th, 2007 00:00" datetime.to_formatted_s(:rfc822) # => "Tue, 04 Dec 2007 00:00:00 +0000" datetime.to_formatted_s(:iso8601) # => "2007-12-04T00:00:00+00:00"
Adding your own datetime formats to to_formatted_s
¶ ↑
DateTime
formats are shared with Time
. You can add your own to the Time::DATE_FORMATS hash. Use the format name as the hash key and either a strftime string or Proc instance that takes a time or datetime argument as the value.
# config/initializers/time_formats.rb Time::DATE_FORMATS[:month_and_year] = '%B %Y' Time::DATE_FORMATS[:short_ordinal] = lambda { |time| time.strftime("%B #{time.day.ordinalize}") }
# File lib/active_support/core_ext/date_time/conversions.rb, line 35 def to_formatted_s(format = :default) if formatter = ::Time::DATE_FORMATS[format] formatter.respond_to?(:call) ? formatter.call(self).to_s : strftime(formatter) else to_default_s end end
Converts self
to an integer number of seconds since the Unix epoch.
# File lib/active_support/core_ext/date_time/conversions.rb, line 84 def to_i seconds_since_unix_epoch.to_i end
Either return an instance of Time
with the same UTC offset as self
or an instance of Time
representing the same time in the local system timezone depending on the setting of on the setting of ActiveSupport.to_time_preserves_timezone
.
# File lib/active_support/core_ext/date_time/compatibility.rb, line 15 def to_time preserve_timezone ? getlocal(utc_offset) : getlocal end
Returns the fraction of a second as microseconds
# File lib/active_support/core_ext/date_time/conversions.rb, line 89 def usec (sec_fraction * 1_000_000).to_i end
Returns a Time
instance of the simultaneous time in the UTC timezone.
DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)) # => Mon, 21 Feb 2005 10:11:12 -0600 DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)).utc # => Mon, 21 Feb 2005 16:11:12 UTC
# File lib/active_support/core_ext/date_time/calculations.rb, line 180 def utc utc = new_offset(0) Time.utc( utc.year, utc.month, utc.day, utc.hour, utc.min, utc.sec + utc.sec_fraction ) end
Returns true
if offset == 0
.
# File lib/active_support/core_ext/date_time/calculations.rb, line 193 def utc? offset == 0 end
Returns the offset value in seconds.
# File lib/active_support/core_ext/date_time/calculations.rb, line 198 def utc_offset (offset * 86400).to_i end
Private Instance Methods
# File lib/active_support/core_ext/date_time/conversions.rb, line 99 def offset_in_seconds (offset * 86400).to_i end
# File lib/active_support/core_ext/date_time/conversions.rb, line 103 def seconds_since_unix_epoch (jd - 2440588) * 86400 - offset_in_seconds + seconds_since_midnight end