Class: DateTime

Inherits:
Object show all
Defined in:
activesupport/lib/active_support/json/encoding.rb,
activesupport/lib/active_support/core_ext/date_time/zones.rb,
activesupport/lib/active_support/core_ext/date_time/acts_like.rb,
activesupport/lib/active_support/core_ext/date_time/conversions.rb,
activesupport/lib/active_support/core_ext/date_time/calculations.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.civil_from_format(utc_or_local, year, month = 1, day = 1, hour = 0, min = 0, sec = 0) ⇒ Object

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

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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 64

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

.currentObject

Returns Time.zone.now.to_datetime when Time.zone or config.time_zone are set, otherwise returns Time.now.to_datetime.


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 8

def current
  ::Time.zone ? ::Time.zone.now.to_datetime : ::Time.now.to_datetime
end

Instance Method Details

#<=>(other) ⇒ Object

Layers additional behavior on DateTime#<=> so that Time and ActiveSupport::TimeWithZone instances can be compared with a DateTime.


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 153

def <=>(other)
  super other.to_datetime
end

#acts_like_date?Boolean

Duck-types as a Date-like class. See Object#acts_like?.

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/core_ext/date_time/acts_like.rb', line 6

def acts_like_date?
  true
end

#acts_like_time?Boolean

Duck-types as a Time-like class. See Object#acts_like?.

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/core_ext/date_time/acts_like.rb', line 11

def acts_like_time?
  true
end

#advance(options) ⇒ Object

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.


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 65

def advance(options)
  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

#ago(seconds) ⇒ Object

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!


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 82

def ago(seconds)
  since(-seconds)
end

#as_json(options = nil) ⇒ Object

:nodoc:


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# File 'activesupport/lib/active_support/json/encoding.rb', line 337

def as_json(options = nil) #:nodoc:
  if ActiveSupport.use_standard_json_time_format
    xmlschema
  else
    strftime('%Y/%m/%d %H:%M:%S %z')
  end
end

#beginning_of_dayObject Also known as: midnight, at_midnight, at_beginning_of_day

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


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 95

def beginning_of_day
  change(:hour => 0)
end

#beginning_of_hourObject Also known as: at_beginning_of_hour

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


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 109

def beginning_of_hour
  change(:min => 0)
end

#beginning_of_minuteObject Also known as: at_beginning_of_minute

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


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 121

def beginning_of_minute
  change(:sec => 0)
end

#change(options) ⇒ Object

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)

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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 48

def change(options)
  ::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 + sec_fraction),
    options.fetch(:offset, offset),
    options.fetch(:start, start)
  )
end

#end_of_dayObject Also known as: at_end_of_day

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


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 103

def end_of_day
  change(:hour => 23, :min => 59, :sec => 59)
end

#end_of_hourObject Also known as: at_end_of_hour

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


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 115

def end_of_hour
  change(:min => 59, :sec => 59)
end

#end_of_minuteObject Also known as: at_end_of_minute

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


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 127

def end_of_minute
  change(:sec => 59)
end

#formatted_offset(colon = true, alternate_utc_string = nil) ⇒ Object

datetime = DateTime.civil(2000, 1, 1, 0, 0, 0, Rational(-6, 24))

datetime.formatted_offset         # => "-06:00"
datetime.formatted_offset(false)  # => "-0600"

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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 46

def formatted_offset(colon = true, alternate_utc_string = nil)
  utc? && alternate_utc_string || ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, colon)
end

#future?Boolean

Tells whether the DateTime object's datetime lies in the future.

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 19

def future?
  self > ::DateTime.current
end

#in_time_zone(zone = ::Time.zone) ⇒ Object

Returns the simultaneous time in Time.zone.

Time.zone = 'Hawaii'             # => 'Hawaii'
DateTime.new(2000).in_time_zone  # => Fri, 31 Dec 1999 14:00:00 HST -10:00

This method is similar to Time#localtime, except that it uses Time.zone as the local zone instead of the operating system's time zone.

You can also pass in a TimeZone instance or string that identifies a TimeZone as an argument, and the conversion will be based on that zone instead of Time.zone.

DateTime.new(2000).in_time_zone('Alaska') # => Fri, 31 Dec 1999 15:00:00 AKST -09:00

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# File 'activesupport/lib/active_support/core_ext/date_time/zones.rb', line 18

def in_time_zone(zone = ::Time.zone)
  if zone
    ActiveSupport::TimeWithZone.new(utc? ? self : getutc, ::Time.find_zone!(zone))
  else
    self
  end
end

#nsecObject

Returns the fraction of a second as nanoseconds


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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 89

def nsec
  (sec_fraction * 1_000_000_000).to_i
end

#past?Boolean

Tells whether the DateTime object's datetime lies in the past.

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 14

def past?
  self < ::DateTime.current
end

#readable_inspectObject Also known as: inspect

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


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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 51

def readable_inspect
  to_s(:rfc822)
end

#seconds_since_midnightObject

Seconds since midnight: DateTime.now.seconds_since_midnight.


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 24

def seconds_since_midnight
  sec + (min * 60) + (hour * 3600)
end

#seconds_until_end_of_dayObject

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

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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 33

def seconds_until_end_of_day
  end_of_day.to_i - to_i
end

#since(seconds) ⇒ Object Also known 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!


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 89

def since(seconds)
  self + Rational(seconds.round, 86400)
end

#to_fObject

Converts self to a floating-point number of seconds since the Unix epoch.


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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 74

def to_f
  seconds_since_unix_epoch.to_f
end

#to_formatted_s(format = :default) ⇒ Object Also known as: to_s

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"

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}") }

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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 32

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

#to_iObject

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


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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 79

def to_i
  seconds_since_unix_epoch.to_i
end

#usecObject

Returns the fraction of a second as microseconds


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# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 84

def usec
  (sec_fraction * 1_000_000).to_i
end

#utcObject Also known as: getutc

Adjusts DateTime to UTC by adding its offset value; offset is set to 0.

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 +0000

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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 136

def utc
  new_offset(0)
end

#utc?Boolean

Returns true if offset == 0.

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 142

def utc?
  offset == 0
end

#utc_offsetObject

Returns the offset value in seconds.


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# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 147

def utc_offset
  (offset * 86400).to_i
end