Class: ActiveSupport::TimeZone

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain: self, Comparable
Inherits:	Object
Defined in:	activesupport/lib/active_support/values/time_zone.rb

Overview

The TimeZone class serves as a wrapper around TZInfo::Timezone instances. It allows us to do the following:

Limit the set of zones provided by TZInfo to a meaningful subset of 146 zones.
Retrieve and display zones with a friendlier name (e.g., “Eastern Time (US & Canada)” instead of “America/New_York”).
Lazily load TZInfo::Timezone instances only when they're needed.
Create TimeWithZone instances via TimeZone's #local, parse, at and now methods.

If you set config.time_zone in the ::Rails Application, you can access this TimeZone object via Time.zone:

# application.rb:
class Application < Rails::Application
  config.time_zone = 'Eastern Time (US & Canada)'
end

Time.zone      # => #<TimeZone:0x514834...>
Time.zone.name # => "Eastern Time (US & Canada)"
Time.zone.now  # => Sun, 18 May 2008 14:30:44 EDT -04:00

The version of TZInfo bundled with Active Support only includes the definitions necessary to support the zones defined by the TimeZone class. If you need to use zones that aren't defined by TimeZone, you'll need to install the TZInfo gem (if a recent version of the gem is installed locally, this will be used instead of the bundled version.)

Constant Summary

MAPPING =

Keys are ::Rails TimeZone names, values are TZInfo identifiers.

# File 'activesupport/lib/active_support/values/time_zone.rb', line 37

{
  "International Date Line West" => "Pacific/Midway",
  "Midway Island"                => "Pacific/Midway",
  "American Samoa"               => "Pacific/Pago_Pago",
  "Hawaii"                       => "Pacific/Honolulu",
  "Alaska"                       => "America/Juneau",
  "Pacific Time (US & Canada)"   => "America/Los_Angeles",
  "Tijuana"                      => "America/Tijuana",
  "Mountain Time (US & Canada)"  => "America/Denver",
  "Arizona"                      => "America/Phoenix",
  "Chihuahua"                    => "America/Chihuahua",
  "Mazatlan"                     => "America/Mazatlan",
  "Central Time (US & Canada)"   => "America/Chicago",
  "Saskatchewan"                 => "America/Regina",
  "Guadalajara"                  => "America/Mexico_City",
  "Mexico City"                  => "America/Mexico_City",
  "Monterrey"                    => "America/Monterrey",
  "Central America"              => "America/Guatemala",
  "Eastern Time (US & Canada)"   => "America/New_York",
  "Indiana (East)"               => "America/Indiana/Indianapolis",
  "Bogota"                       => "America/Bogota",
  "Lima"                         => "America/Lima",
  "Quito"                        => "America/Lima",
  "Atlantic Time (Canada)"       => "America/Halifax",
  "Caracas"                      => "America/Caracas",
  "La Paz"                       => "America/La_Paz",
  "Santiago"                     => "America/Santiago",
  "Newfoundland"                 => "America/St_Johns",
  "Brasilia"                     => "America/Sao_Paulo",
  "Buenos Aires"                 => "America/Argentina/Buenos_Aires",
  "Montevideo"                   => "America/Montevideo",
  "Georgetown"                   => "America/Guyana",
  "Greenland"                    => "America/Godthab",
  "Mid-Atlantic"                 => "Atlantic/South_Georgia",
  "Azores"                       => "Atlantic/Azores",
  "Cape Verde Is."               => "Atlantic/Cape_Verde",
  "Dublin"                       => "Europe/Dublin",
  "Edinburgh"                    => "Europe/London",
  "Lisbon"                       => "Europe/Lisbon",
  "London"                       => "Europe/London",
  "Casablanca"                   => "Africa/Casablanca",
  "Monrovia"                     => "Africa/Monrovia",
  "UTC"                          => "Etc/UTC",
  "Belgrade"                     => "Europe/Belgrade",
  "Bratislava"                   => "Europe/Bratislava",
  "Budapest"                     => "Europe/Budapest",
  "Ljubljana"                    => "Europe/Ljubljana",
  "Prague"                       => "Europe/Prague",
  "Sarajevo"                     => "Europe/Sarajevo",
  "Skopje"                       => "Europe/Skopje",
  "Warsaw"                       => "Europe/Warsaw",
  "Zagreb"                       => "Europe/Zagreb",
  "Brussels"                     => "Europe/Brussels",
  "Copenhagen"                   => "Europe/Copenhagen",
  "Madrid"                       => "Europe/Madrid",
  "Paris"                        => "Europe/Paris",
  "Amsterdam"                    => "Europe/Amsterdam",
  "Berlin"                       => "Europe/Berlin",
  "Bern"                         => "Europe/Berlin",
  "Rome"                         => "Europe/Rome",
  "Stockholm"                    => "Europe/Stockholm",
  "Vienna"                       => "Europe/Vienna",
  "West Central Africa"          => "Africa/Algiers",
  "Bucharest"                    => "Europe/Bucharest",
  "Cairo"                        => "Africa/Cairo",
  "Helsinki"                     => "Europe/Helsinki",
  "Kyiv"                         => "Europe/Kiev",
  "Riga"                         => "Europe/Riga",
  "Sofia"                        => "Europe/Sofia",
  "Tallinn"                      => "Europe/Tallinn",
  "Vilnius"                      => "Europe/Vilnius",
  "Athens"                       => "Europe/Athens",
  "Istanbul"                     => "Europe/Istanbul",
  "Minsk"                        => "Europe/Minsk",
  "Jerusalem"                    => "Asia/Jerusalem",
  "Harare"                       => "Africa/Harare",
  "Pretoria"                     => "Africa/Johannesburg",
  "Kaliningrad"                  => "Europe/Kaliningrad",
  "Moscow"                       => "Europe/Moscow",
  "St. Petersburg"               => "Europe/Moscow",
  "Volgograd"                    => "Europe/Volgograd",
  "Samara"                       => "Europe/Samara",
  "Kuwait"                       => "Asia/Kuwait",
  "Riyadh"                       => "Asia/Riyadh",
  "Nairobi"                      => "Africa/Nairobi",
  "Baghdad"                      => "Asia/Baghdad",
  "Tehran"                       => "Asia/Tehran",
  "Abu Dhabi"                    => "Asia/Muscat",
  "Muscat"                       => "Asia/Muscat",
  "Baku"                         => "Asia/Baku",
  "Tbilisi"                      => "Asia/Tbilisi",
  "Yerevan"                      => "Asia/Yerevan",
  "Kabul"                        => "Asia/Kabul",
  "Ekaterinburg"                 => "Asia/Yekaterinburg",
  "Islamabad"                    => "Asia/Karachi",
  "Karachi"                      => "Asia/Karachi",
  "Tashkent"                     => "Asia/Tashkent",
  "Chennai"                      => "Asia/Kolkata",
  "Kolkata"                      => "Asia/Kolkata",
  "Mumbai"                       => "Asia/Kolkata",
  "New Delhi"                    => "Asia/Kolkata",
  "Kathmandu"                    => "Asia/Kathmandu",
  "Astana"                       => "Asia/Dhaka",
  "Dhaka"                        => "Asia/Dhaka",
  "Sri Jayawardenepura"          => "Asia/Colombo",
  "Almaty"                       => "Asia/Almaty",
  "Novosibirsk"                  => "Asia/Novosibirsk",
  "Rangoon"                      => "Asia/Rangoon",
  "Bangkok"                      => "Asia/Bangkok",
  "Hanoi"                        => "Asia/Bangkok",
  "Jakarta"                      => "Asia/Jakarta",
  "Krasnoyarsk"                  => "Asia/Krasnoyarsk",
  "Beijing"                      => "Asia/Shanghai",
  "Chongqing"                    => "Asia/Chongqing",
  "Hong Kong"                    => "Asia/Hong_Kong",
  "Urumqi"                       => "Asia/Urumqi",
  "Kuala Lumpur"                 => "Asia/Kuala_Lumpur",
  "Singapore"                    => "Asia/Singapore",
  "Taipei"                       => "Asia/Taipei",
  "Perth"                        => "Australia/Perth",
  "Irkutsk"                      => "Asia/Irkutsk",
  "Ulaanbaatar"                  => "Asia/Ulaanbaatar",
  "Seoul"                        => "Asia/Seoul",
  "Osaka"                        => "Asia/Tokyo",
  "Sapporo"                      => "Asia/Tokyo",
  "Tokyo"                        => "Asia/Tokyo",
  "Yakutsk"                      => "Asia/Yakutsk",
  "Darwin"                       => "Australia/Darwin",
  "Adelaide"                     => "Australia/Adelaide",
  "Canberra"                     => "Australia/Melbourne",
  "Melbourne"                    => "Australia/Melbourne",
  "Sydney"                       => "Australia/Sydney",
  "Brisbane"                     => "Australia/Brisbane",
  "Hobart"                       => "Australia/Hobart",
  "Vladivostok"                  => "Asia/Vladivostok",
  "Guam"                         => "Pacific/Guam",
  "Port Moresby"                 => "Pacific/Port_Moresby",
  "Magadan"                      => "Asia/Magadan",
  "Srednekolymsk"                => "Asia/Srednekolymsk",
  "Solomon Is."                  => "Pacific/Guadalcanal",
  "New Caledonia"                => "Pacific/Noumea",
  "Fiji"                         => "Pacific/Fiji",
  "Kamchatka"                    => "Asia/Kamchatka",
  "Marshall Is."                 => "Pacific/Majuro",
  "Auckland"                     => "Pacific/Auckland",
  "Wellington"                   => "Pacific/Auckland",
  "Nuku'alofa"                   => "Pacific/Tongatapu",
  "Tokelau Is."                  => "Pacific/Fakaofo",
  "Chatham Is."                  => "Pacific/Chatham",
  "Samoa"                        => "Pacific/Apia"
}

UTC_OFFSET_WITHOUT_COLON =
# File 'activesupport/lib/active_support/values/time_zone.rb', line 190
```
UTC_OFFSET_WITH_COLON.tr(':', '')
```
UTC_OFFSET_WITH_COLON =
# File 'activesupport/lib/active_support/values/time_zone.rb', line 189
```
'%s%02d:%02d'
```

Class Method Summary

.[](arg)

Locate a specific time zone object.
.all

Returns an array of all TimeZone objects.
.create
.find_tzinfo(name)
.new(name) ⇒ TimeZone constructor

Returns a TimeZone instance with the given name, or nil if no such TimeZone instance exists.
.seconds_to_utc_offset(seconds, colon = true)

Assumes self represents an offset from UTC in seconds (as returned from Time#utc_offset) and turns this into an +HH:MM formatted string.
.us_zones

A convenience method for returning a collection of TimeZone objects for time zones in the USA.

Instance Attribute Summary

#name readonly
#tzinfo readonly

Instance Method Summary

#<=>(zone)

Compare this time zone to the parameter.
#=~(re)

Compare #name and TZInfo identifier to a supplied regexp, returning true if a match is found.
#at(secs)

::Method for creating new TimeWithZone instance in time zone of self from number of seconds since the Unix epoch.
#formatted_offset(colon = true, alternate_utc_string = nil)

Returns the offset of this time zone as a formatted string, of the format “+HH:MM”.
#initialize(name, utc_offset = nil, tzinfo = nil) ⇒ TimeZone constructor

Create a new TimeZone object with the given name and offset.
#local(*args)

::Method for creating new TimeWithZone instance in time zone of self from given values.
#local_to_utc(time, dst = true)

Adjust the given time to the simultaneous time in UTC.
#now

Returns an TimeWithZone instance representing the current time in the time zone represented by self.
#parse(str, now = now())

::Method for creating new TimeWithZone instance in time zone of self from parsed string.
#period_for_local(time, dst = true)

Available so that TimeZone instances respond like TZInfo::Timezone instances.
#period_for_utc(time)

Available so that TimeZone instances respond like TZInfo::Timezone instances.
#to_s

Returns a textual representation of this time zone.
#today

Return the current date in this time zone.
#tomorrow

Returns the next date in this time zone.
#utc_offset

Returns the offset of this time zone from UTC in seconds.
#utc_to_local(time)

Adjust the given time to the simultaneous time in the time zone represented by self.
#yesterday

Returns the previous date in this time zone.

Constructor Details

.new(name) ⇒ `TimeZone`

Returns a TimeZone instance with the given name, or nil if no such TimeZone instance exists. (This exists to support the use of this class with the composed_of macro.)

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 216


def new(name)
  self[name]
end

#initialize(name, utc_offset = nil, tzinfo = nil) ⇒ `TimeZone`

Create a new TimeZone object with the given name and offset. The offset is the number of seconds that this time zone is offset from UTC (GMT). Seconds were chosen as the offset unit because that is the unit that Ruby uses to represent time zone offsets (see Time#utc_offset).

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 270


def initialize(name, utc_offset = nil, tzinfo = nil)
  @name = name
  @utc_offset = utc_offset
  @tzinfo = tzinfo || TimeZone.find_tzinfo(name)
end

Class Method Details

.[](arg)

Locate a specific time zone object. If the argument is a string, it is interpreted to mean the name of the timezone to locate. If it is a numeric value it is either the hour offset, or the second offset, of the timezone to find. (The first one with that offset will be returned.) Returns nil if no such time zone is known to the system.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 239


def [](arg)
  case arg
    when String
    begin
      @lazy_zones_map[arg] ||= create(arg).tap { |tz| tz.utc_offset }
    rescue TZInfo::InvalidTimezoneIdentifier
      nil
    end
    when Numeric, ActiveSupport::Duration
      arg *= 3600 if arg.abs <= 13
      all.find { |z| z.utc_offset == arg.to_i }
    else
      raise ArgumentError, "invalid argument to TimeZone[]: #{arg.inspect}"
  end
end

.all

Returns an array of all TimeZone objects. There are multiple TimeZone objects per time zone, in many cases, to make it easier for users to find their own time zone.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 223


def all
  @zones ||= zones_map.values.sort
end

.create

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 211


alias_method :create, :new

.find_tzinfo(name)

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 207


def find_tzinfo(name)
  TZInfo::TimezoneProxy.new(MAPPING[name] || name)
end

.seconds_to_utc_offset(seconds, colon = true)

Assumes self represents an offset from UTC in seconds (as returned from Time#utc_offset) and turns this into an +HH:MM formatted string.

TimeZone.seconds_to_utc_offset(-21_600) # => "-06:00"

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 199


def seconds_to_utc_offset(seconds, colon = true)
  format = colon ? UTC_OFFSET_WITH_COLON : UTC_OFFSET_WITHOUT_COLON
  sign = (seconds < 0 ? '-' : '+')
  hours = seconds.abs / 3600
  minutes = (seconds.abs % 3600) / 60
  format % [sign, hours, minutes]
end

.us_zones

A convenience method for returning a collection of TimeZone objects for time zones in the USA.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 257


def us_zones
  @us_zones ||= all.find_all { |z| z.name =~ /US|Arizona|Indiana|Hawaii|Alaska/ }
end

Instance Attribute Details

#name (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 263


attr_reader :name

#tzinfo (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 264


attr_reader :tzinfo

Instance Method Details

#<=>(zone)

Compare this time zone to the parameter. The two are compared first on their offsets, and then by name.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 297


def <=>(zone)
  return unless zone.respond_to? :utc_offset
  result = (utc_offset <=> zone.utc_offset)
  result = (name <=> zone.name) if result == 0
  result
end

#=~(re)

Compare #name and TZInfo identifier to a supplied regexp, returning true if a match is found.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 306


def =~(re)
  re === name || re === MAPPING[name]
end

#at(secs)

::Method for creating new TimeWithZone instance in time zone of self from number of seconds since the Unix epoch.

Time.zone = 'Hawaii'        # => "Hawaii"
Time.utc(2000).to_f         # => 946684800.0
Time.zone.at(946684800.0)   # => Fri, 31 Dec 1999 14:00:00 HST -10:00

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 331


def at(secs)
  Time.at(secs).utc.in_time_zone(self)
end

#formatted_offset(colon = true, alternate_utc_string = nil)

Returns the offset of this time zone as a formatted string, of the format “+HH:MM”.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 291


def formatted_offset(colon=true, alternate_utc_string = nil)
  utc_offset == 0 && alternate_utc_string || self.class.seconds_to_utc_offset(utc_offset, colon)
end

#local(*args)

::Method for creating new TimeWithZone instance in time zone of self from given values.

Time.zone = 'Hawaii'                    # => "Hawaii"
Time.zone.local(2007, 2, 1, 15, 30, 45) # => Thu, 01 Feb 2007 15:30:45 HST -10:00

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 320


def local(*args)
  time = Time.utc(*args)
  ActiveSupport::TimeWithZone.new(nil, self, time)
end

#local_to_utc(time, dst = true)

Adjust the given time to the simultaneous time in UTC. Returns a Time.utc() instance.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 405


def local_to_utc(time, dst=true)
  tzinfo.local_to_utc(time, dst)
end

#now

Returns an TimeWithZone instance representing the current time in the time zone represented by self.

Time.zone = 'Hawaii'  # => "Hawaii"
Time.zone.now         # => Wed, 23 Jan 2008 20:24:27 HST -10:00

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 377


def now
  time_now.utc.in_time_zone(self)
end

#parse(str, now = now())

::Method for creating new TimeWithZone instance in time zone of self from parsed string.

Time.zone = 'Hawaii'                   # => "Hawaii"
Time.zone.parse('1999-12-31 14:00:00') # => Fri, 31 Dec 1999 14:00:00 HST -10:00

If upper components are missing from the string, they are supplied from #now:

Time.zone.now               # => Fri, 31 Dec 1999 14:00:00 HST -10:00
Time.zone.parse('22:30:00') # => Fri, 31 Dec 1999 22:30:00 HST -10:00

However, if the date component is not provided, but any other upper components are supplied, then the day of the month defaults to 1:

Time.zone.parse('Mar 2000') # => Wed, 01 Mar 2000 00:00:00 HST -10:00

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 351


def parse(str, now=now())
  parts = Date._parse(str, false)
  return if parts.empty?

  time = Time.new(
    parts.fetch(:year, now.year),
    parts.fetch(:mon, now.month),
    parts.fetch(:mday, parts[:year] || parts[:mon] ? 1 : now.day),
    parts.fetch(:hour, 0),
    parts.fetch(:min, 0),
    parts.fetch(:sec, 0) + parts.fetch(:sec_fraction, 0),
    parts.fetch(:offset, 0)
  )

  if parts[:offset]
    TimeWithZone.new(time.utc, self)
  else
    TimeWithZone.new(nil, self, time)
  end
end

#period_for_local(time, dst = true)

Available so that TimeZone instances respond like TZInfo::Timezone instances.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 417


def period_for_local(time, dst=true)
  tzinfo.period_for_local(time, dst)
end

#period_for_utc(time)

Available so that TimeZone instances respond like TZInfo::Timezone instances.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 411


def period_for_utc(time)
  tzinfo.period_for_utc(time)
end

#to_s

Returns a textual representation of this time zone.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 311


def to_s
  "(GMT#{formatted_offset}) #{name}"
end

#today

Return the current date in this time zone.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 382


def today
  tzinfo.now.to_date
end

#tomorrow

Returns the next date in this time zone.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 387


def tomorrow
  today + 1
end

#utc_offset

Returns the offset of this time zone from UTC in seconds.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 281


def utc_offset
  if @utc_offset
    @utc_offset
  else
    tzinfo.current_period.utc_offset if tzinfo && tzinfo.current_period
  end
end

#utc_to_local(time)

Adjust the given time to the simultaneous time in the time zone represented by self. Returns a Time.utc() instance – if you want an TimeWithZone instance, use Time#in_time_zone() instead.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 399


def utc_to_local(time)
  tzinfo.utc_to_local(time)
end

#yesterday

Returns the previous date in this time zone.

[ GitHub ]

# File 'activesupport/lib/active_support/values/time_zone.rb', line 392


def yesterday
  today - 1
end

Class: ActiveSupport::TimeZone

Overview

Constant Summary

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(name) ⇒ TimeZone

#initialize(name, utc_offset = nil, tzinfo = nil) ⇒ TimeZone

Class Method Details

.[](arg)

.all

.create

.find_tzinfo(name)

.seconds_to_utc_offset(seconds, colon = true)

.us_zones

Instance Attribute Details

#name (readonly)

#tzinfo (readonly)

Instance Method Details

#<=>(zone)

#=~(re)

#at(secs)

#formatted_offset(colon = true, alternate_utc_string = nil)

#local(*args)

#local_to_utc(time, dst = true)

#now

#parse(str, now = now())

#period_for_local(time, dst = true)

#period_for_utc(time)

#to_s

#today

#tomorrow

#utc_offset

#utc_to_local(time)

#yesterday

.new(name) ⇒ `TimeZone`

#initialize(name, utc_offset = nil, tzinfo = nil) ⇒ `TimeZone`