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class DateTime

Inherits From

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
Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 73
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.

Source code GitHub
# File activesupport/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.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 208
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?.

Source code GitHub
# File activesupport/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?.

Source code GitHub
# File activesupport/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.

Just like Date#advance, increments are applied in order of time units from largest to smallest. This order can affect the result around the end of a month.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 82
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!

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 109
def ago(seconds)
  since(-seconds)
end

Alias for: beginning_of_day.

Alias for: beginning_of_hour.

Alias for: beginning_of_minute.

Alias for: end_of_day.

Alias for: end_of_hour.

Alias for: end_of_minute.

Alias for: middle_of_day.

Alias for: middle_of_day.

Alias for: beginning_of_day.

Alias for: middle_of_day.

Also aliased as: midnight, at_midnight, at_beginning_of_day.

Returns a new DateTime representing the start of the day (0:00).

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 122
def beginning_of_day
  change(hour: 0)
end

Also aliased as: at_beginning_of_hour.

Returns a new DateTime representing the start of the hour (hh:00:00).

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 146
def beginning_of_hour
  change(min: 0)
end

Also aliased as: at_beginning_of_minute.

Returns a new DateTime representing the start of the minute (hh:mm:00).

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 158
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)
Source code GitHub
# File activesupport/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

Alias for: inspect.

Also aliased as: at_end_of_day.

Returns a new DateTime representing the end of the day (23:59:59).

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 140
def end_of_day
  change(hour: 23, min: 59, sec: 59, usec: Rational(999999999, 1000))
end

Also aliased as: at_end_of_hour.

Returns a new DateTime representing the end of the hour (hh:59:59).

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 152
def end_of_hour
  change(min: 59, sec: 59, usec: Rational(999999999, 1000))
end

Also aliased as: at_end_of_minute.

Returns a new DateTime representing the end of the minute (hh:mm:59).

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 164
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"
Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 55
def formatted_offset(colon = true, alternate_utc_string = nil)
  utc? && alternate_utc_string || ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, colon)
end

Alias for: utc.

Alias for: localtime.

Alias for: utc.

Alias for: utc.

Alias for: since.

Also aliased as: default_inspect.

Alias for: readable_inspect.

Also aliased as: getlocal.

Returns a Time instance of the simultaneous time in the system timezone.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 170
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

Alias for: middle_of_day.

Also aliased as: midday, noon, at_midday, at_noon, at_middle_of_day.

Returns a new DateTime representing the middle of the day (12:00)

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 130
def middle_of_day
  change(hour: 12)
end

Alias for: beginning_of_day.

Alias for: middle_of_day.

Returns the fraction of a second as nanoseconds

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 98
def nsec
  (sec_fraction * 1_000_000_000).to_i
end

Also aliased as: inspect.

Overrides the default inspect method with a human readable one, e.g., “Mon, 21 Feb 2005 14:30:00 +0000”.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 60
def readable_inspect
  to_fs(: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
Source code GitHub
# File activesupport/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
Source code GitHub
# File activesupport/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

Also aliased as: in.

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!

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 116
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)
Source code GitHub
# File activesupport/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.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 83
def to_f
  seconds_since_unix_epoch.to_f + sec_fraction
end

Alias for: to_fs.

Also aliased as: to_formatted_s.

Convert to a formatted string. See Time::DATE_FORMATS for predefined formats.

This method is aliased to to_formatted_s.

Examples

datetime = DateTime.civil(2007, 12, 4, 0, 0, 0, 0)   # => Tue, 04 Dec 2007 00:00:00 +0000

datetime.to_fs(:db)            # => "2007-12-04 00:00:00"
datetime.to_formatted_s(:db)   # => "2007-12-04 00:00:00"
datetime.to_fs(:number)        # => "20071204000000"
datetime.to_fs(:short)         # => "04 Dec 00:00"
datetime.to_fs(:long)          # => "December 04, 2007 00:00"
datetime.to_fs(:long_ordinal)  # => "December 4th, 2007 00:00"
datetime.to_fs(:rfc822)        # => "Tue, 04 Dec 2007 00:00:00 +0000"
datetime.to_fs(:iso8601)       # => "2007-12-04T00:00:00+00:00"

Adding your own datetime formats to to_fs

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}") }
Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 35
def to_fs(format = :default)
  if formatter = ::Time::DATE_FORMATS[format]
    formatter.respond_to?(:call) ? formatter.call(self).to_s : strftime(formatter)
  else
    to_s
  end
end

Converts self to an integer number of seconds since the Unix epoch.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 88
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.

Source code GitHub
# File activesupport/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

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 93
def usec
  (sec_fraction * 1_000_000).to_i
end

Also aliased as: getgm, getutc, gmtime.

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
Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 184
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.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 197
def utc?
  offset == 0
end

Returns the offset value in seconds.

Source code GitHub
# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 202
def utc_offset
  (offset * 86400).to_i
end

Definition files