Methods
Public Class methods
civil_from_format(utc_or_local, year, month=1, day=1, hour=0, min=0, sec=0)
  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 77
def self.civil_from_format(utc_or_local, year, month=1, day=1, hour=0, min=0, sec=0)
  offset = utc_or_local.to_sym == :local ? local_offset : 0
  civil(year, month, day, hour, min, sec, offset)
end
current()

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

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 13
def current
  ::Time.zone ? ::Time.zone.now.to_datetime : ::Time.now.to_datetime
end
local_offset()

DateTimes aren’t aware of DST rules, so use a consistent non-DST offset when creating a DateTime with an offset in the local zone

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 8
def local_offset
  ::Time.local(2007).utc_offset.to_r / 86400
end
Public Instance methods
acts_like_date?()

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

  # File activesupport/lib/active_support/core_ext/date_time/acts_like.rb, line 5
def acts_like_date?
  true
end
acts_like_time?()

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

  # File activesupport/lib/active_support/core_ext/date_time/acts_like.rb, line 10
def acts_like_time?
  true
end
advance(options)

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 activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 53
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[:seconds] || 0) + (options[:minutes] || 0) * 60 + (options[:hours] || 0) * 3600
  seconds_to_advance == 0 ? datetime_advanced_by_date : datetime_advanced_by_date.since(seconds_to_advance)
end
ago(seconds)

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 activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 62
def ago(seconds)
  since(-seconds)
end
beginning_of_day()

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

This method is also aliased as midnight at_midnight at_beginning_of_day
  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 74
def beginning_of_day
  change(:hour => 0)
end
change(options)

Returns a new DateTime where one or more of the elements have been changed according to the options parameter. The time options (hour, minute, 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.

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 36
def change(options)
  ::DateTime.civil(
    options[:year]  || year,
    options[:month] || month,
    options[:day]   || day,
    options[:hour]  || hour,
    options[:min]   || (options[:hour] ? 0 : min),
    options[:sec]   || ((options[:hour] || options[:min]) ? 0 : sec),
    options[:offset]  || offset,
    options[:start]  || start
  )
end
compare_with_coercion(other)

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

This method is also aliased as <=>
  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 108
def compare_with_coercion(other)
  other = other.comparable_time if other.respond_to?(:comparable_time)
  other = other.to_datetime unless other.acts_like?(:date)
  compare_without_coercion(other)
end
end_of_day()

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

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 82
def end_of_day
  change(:hour => 23, :min => 59, :sec => 59)
end
formatted_offset(colon = true, alternate_utc_string = nil)

Returns the utc_offset as an +HH:MM formatted string. Examples:

datetime = DateTime.civil(2000, 1, 1, 0, 0, 0, Rational(-6, 24))
datetime.formatted_offset         # => "-06:00"
datetime.formatted_offset(false)  # => "-0600"
  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 50
def formatted_offset(colon = true, alternate_utc_string = nil)
  utc? && alternate_utc_string || ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, colon)
end
future?()

Tells whether the DateTime object’s datetime lies in the future

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 24
def future?
  self > ::DateTime.current
end
in_time_zone(zone = ::Time.zone)

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
  # File activesupport/lib/active_support/core_ext/date_time/zones.rb, line 16
def in_time_zone(zone = ::Time.zone)
  return self unless zone

  ActiveSupport::TimeWithZone.new(utc? ? self : getutc, ::Time.__send__(:get_zone, zone))
end
past?()

Tells whether the DateTime object’s datetime lies in the past

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 19
def past?
  self < ::DateTime.current
end
readable_inspect()

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

This method is also aliased as inspect
  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 55
def readable_inspect
  to_s(:rfc822)
end
seconds_since_midnight()

Seconds since midnight: DateTime.now.seconds_since_midnight

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 29
def seconds_since_midnight
  sec + (min * 60) + (hour * 3600)
end
since(seconds)

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!

This method is also aliased as in
  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 68
def since(seconds)
  self + Rational(seconds.round, 86400)
end
to_date()

Converts self to a Ruby Date object; time portion is discarded

  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 62
def to_date
  ::Date.new(year, month, day)
end
to_datetime()

To be able to keep Times, Dates and DateTimes interchangeable on conversions

  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 73
def to_datetime
  self
end
to_f()

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

  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 88
def to_f
  seconds_since_unix_epoch.to_f
end
to_formatted_s(format = :default)

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}") }
This method is also aliased as to_s
  # File activesupport/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
to_i()

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

  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 93
def to_i
  seconds_since_unix_epoch.to_i
end
to_time()

Attempts to convert self to a Ruby Time object; returns self if out of range of Ruby Time class If self has an offset other than 0, self will just be returned unaltered, since there’s no clean way to map it to a Time

  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 68
def to_time
  self.offset == 0 ? ::Time.utc_time(year, month, day, hour, min, sec) : self
end
utc()

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

Example:

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
This method is also aliased as getutc
  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 92
def utc
  new_offset(0)
end
utc?()

Returns true if offset == 0

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 98
def utc?
  offset == 0
end
utc_offset()

Returns the offset value in seconds

  # File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 103
def utc_offset
  (offset * 86400).to_i
end
xmlschema()

Converts datetime to an appropriate format for use in XML

  # File activesupport/lib/active_support/core_ext/date_time/conversions.rb, line 83
def xmlschema
  strftime("%Y-%m-%dT%H:%M:%S%Z")
end