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


77
78
79
80
# 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

.currentObject

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


11
12
13
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 11

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

.local_offsetObject

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


6
7
8
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 6

def local_offset
  ::Time.local(2007).utc_offset.to_r / 86400
end

Instance Method Details

#<=>(other) ⇒ Object

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


129
130
131
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 129

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

#acts_like_date?Boolean

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

Returns:

  • (Boolean)

5
6
7
# File 'activesupport/lib/active_support/core_ext/date_time/acts_like.rb', line 5

def acts_like_date?
  true
end

#acts_like_time?Boolean

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

Returns:

  • (Boolean)

10
11
12
# File 'activesupport/lib/active_support/core_ext/date_time/acts_like.rb', line 10

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.


51
52
53
54
55
56
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 51

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) ⇒ 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!


60
61
62
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 60

def ago(seconds)
  since(-seconds)
end

#as_json(options = nil) ⇒ Object

:nodoc:


280
281
282
283
284
285
286
# File 'activesupport/lib/active_support/json/encoding.rb', line 280

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)


72
73
74
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 72

def beginning_of_day
  change(:hour => 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, 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.


34
35
36
37
38
39
40
41
42
43
44
45
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 34

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

#end_of_dayObject

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


80
81
82
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 80

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

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

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"

50
51
52
# 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?Boolean

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

Returns:

  • (Boolean)

22
23
24
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 22

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

16
17
18
19
20
# 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.find_zone!(zone))
end

#minus_with_duration(other) ⇒ Object Also known as: -

:nodoc:


96
97
98
99
100
101
102
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 96

def minus_with_duration(other) #:nodoc:
  if ActiveSupport::Duration === other
    plus_with_duration(-other)
  else
    minus_without_duration(other)
  end
end

#past?Boolean

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

Returns:

  • (Boolean)

17
18
19
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 17

def past?
  self < ::DateTime.current
end

#plus_with_duration(other) ⇒ Object Also known as: +

:nodoc:


86
87
88
89
90
91
92
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 86

def plus_with_duration(other) #:nodoc:
  if ActiveSupport::Duration === other
    other.since(self)
  else
    plus_without_duration(other)
  end
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”.


55
56
57
# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 55

def readable_inspect
  to_s(:rfc822)
end

#seconds_since_midnightObject

Seconds since midnight: DateTime.now.seconds_since_midnight


27
28
29
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 27

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


66
67
68
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 66

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

#to_dateObject

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


62
63
64
# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 62

def to_date
  ::Date.new(year, month, day)
end

#to_datetimeObject

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


73
74
75
# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 73

def to_datetime
  self
end

#to_fObject

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


88
89
90
# 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) ⇒ 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}") }

35
36
37
38
39
40
41
# 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_iObject

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


93
94
95
# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 93

def to_i
  seconds_since_unix_epoch.to_i
end

#to_timeObject

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.


68
69
70
# 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, sec_fraction * (RUBY_VERSION < '1.9' ? 86400000000 : 1000000)) : self
end

#utcObject Also known as: getutc

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

113
114
115
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 113

def utc
  new_offset(0)
end

#utc?Boolean

Returns true if offset == 0

Returns:

  • (Boolean)

119
120
121
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 119

def utc?
  offset == 0
end

#utc_offsetObject

Returns the offset value in seconds


124
125
126
# File 'activesupport/lib/active_support/core_ext/date_time/calculations.rb', line 124

def utc_offset
  (offset * 86400).to_i
end

#xmlschemaObject

Converts datetime to an appropriate format for use in XML.


83
84
85
# File 'activesupport/lib/active_support/core_ext/date_time/conversions.rb', line 83

def xmlschema
  strftime("%Y-%m-%dT%H:%M:%S%Z")
end