Class TimeZone
In: vendor/rails/activesupport/lib/active_support/values/time_zone.rb
Parent: Object

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 142 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 ActiveSupport::TimeWithZone instances via TimeZone‘s local, parse, at and now methods.

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

  # environment.rb:
  Rails::Initializer.run do |config|
    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.)

Methods

<=>   []   all   at   formatted_offset   local   local_to_utc   new   new   now   parse   period_for_local   period_for_utc   to_s   today   tzinfo   us_zones   utc_offset   utc_to_local  

Included Modules

Comparable

Constants

MAPPING = { "International Date Line West" => "Pacific/Midway", "Midway Island" => "Pacific/Midway", "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/Argentina/Buenos_Aires", "Buenos Aires" => "America/Argentina/Buenos_Aires", "Georgetown" => "America/Argentina/San_Juan", "Greenland" => "America/Godthab", "Mid-Atlantic" => "Atlantic/South_Georgia", "Azores" => "Atlantic/Azores", "Cape Verde Is." => "Atlantic/Cape_Verde", "Dublin" => "Europe/Dublin", "Edinburgh" => "Europe/Dublin", "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", "Kyev" => "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", "Moscow" => "Europe/Moscow", "St. Petersburg" => "Europe/Moscow", "Volgograd" => "Europe/Moscow", "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/Katmandu", "Astana" => "Asia/Dhaka", "Dhaka" => "Asia/Dhaka", "Sri Jayawardenepura" => "Asia/Dhaka", "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", "Ulaan Bataar" => "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", "Solomon Is." => "Asia/Magadan", "New Caledonia" => "Pacific/Noumea", "Fiji" => "Pacific/Fiji", "Kamchatka" => "Asia/Kamchatka", "Marshall Is." => "Pacific/Majuro", "Auckland" => "Pacific/Auckland", "Wellington" => "Pacific/Auckland", "Nuku'alofa" => "Pacific/Tongatapu"   Keys are Rails TimeZone names, values are TZInfo identifiers
ZONES = []
ZONES_MAP = {}
US_ZONES = ZONES.find_all { |z| z.name =~ /US|Arizona|Indiana|Hawaii|Alaska/ }

External Aliases

new -> create

Attributes

name  [R] 

Public Class methods

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.

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 376
376:     def [](arg)
377:       case arg
378:         when String
379:           ZONES_MAP[arg]
380:         when Numeric, ActiveSupport::Duration
381:           arg *= 3600 if arg.abs <= 13
382:           all.find { |z| z.utc_offset == arg.to_i }
383:         else
384:           raise ArgumentError, "invalid argument to TimeZone[]: #{arg.inspect}"
385:       end
386:     end

Return 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.

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 367
367:     def all
368:       ZONES
369:     end

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).

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 179
179:   def initialize(name, utc_offset, tzinfo = nil)
180:     @name = name
181:     @utc_offset = utc_offset
182:     @tzinfo = tzinfo
183:   end

Return 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.)

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 360
360:     def new(name)
361:       self[name]
362:     end

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 390
390:     def us_zones
391:       US_ZONES
392:     end

Public Instance methods

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 197
197:   def <=>(zone)
198:     result = (utc_offset <=> zone.utc_offset)
199:     result = (name <=> zone.name) if result == 0
200:     result
201:   end

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

  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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 222
222:   def at(secs)
223:     utc = Time.at(secs).utc rescue DateTime.civil(1970).since(secs)
224:     utc.in_time_zone(self)
225:   end

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 191
191:   def formatted_offset(colon=true, alternate_utc_string = nil)
192:     utc_offset == 0 && alternate_utc_string || utc_offset.to_utc_offset_s(colon)
193:   end

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

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 212
212:   def local(*args)
213:     time = Time.utc_time(*args)
214:     ActiveSupport::TimeWithZone.new(nil, self, time)
215:   end

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 268
268:   def local_to_utc(time, dst=true)
269:     tzinfo.local_to_utc(time, dst)
270:   end

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

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 252
252:   def now
253:     Time.now.utc.in_time_zone(self)
254:   end

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

  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 TimeZone#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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 236
236:   def parse(str, now=now)
237:     date_parts = Date._parse(str)
238:     return if date_parts.blank?
239:     time = Time.parse(str, now) rescue DateTime.parse(str)
240:     if date_parts[:offset].nil?
241:       ActiveSupport::TimeWithZone.new(nil, self, time)
242:     else
243:       time.in_time_zone(self)
244:     end
245:   end

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 278
278:   def period_for_local(time, dst=true)
279:     tzinfo.period_for_local(time, dst)
280:   end

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 273
273:   def period_for_utc(time)
274:     tzinfo.period_for_utc(time)
275:   end

Returns a textual representation of this time zone.

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 204
204:   def to_s
205:     "(GMT#{formatted_offset}) #{name}"
206:   end

Return the current date in this time zone.

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 257
257:   def today
258:     tzinfo.now.to_date
259:   end

TODO: Preload instead of lazy load for thread safety

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 283
283:   def tzinfo
284:     @tzinfo ||= TZInfo::Timezone.get(MAPPING[name])
285:   end

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 185
185:   def utc_offset
186:     @utc_offset ||= tzinfo.current_period.utc_offset
187:   end

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

[Source]

     # File vendor/rails/activesupport/lib/active_support/values/time_zone.rb, line 263
263:   def utc_to_local(time)
264:     tzinfo.utc_to_local(time)
265:   end

[Validate]