Class: ActiveSupport::TimeZone

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
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 134 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 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      # => #<ActiveSupport::TimeZone:0x514834...>
Time.zone.name # => "Eastern Time (US & Canada)"
Time.zone.now  # => Sun, 18 May 2008 14:30:44 EDT -04:00

Constant Summary collapse

MAPPING =

Keys are Rails TimeZone names, values are TZInfo identifiers.

{
  "International Date Line West" => "Etc/GMT+12",
  "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",
  "Puerto Rico"                  => "America/Puerto_Rico",
  "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/Zurich",
  "Zurich"                       => "Europe/Zurich",
  "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"
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#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).



297
298
299
300
301
# File 'lib/active_support/values/time_zone.rb', line 297

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

Instance Attribute Details

#nameObject (readonly)

Returns the value of attribute name.



290
291
292
# File 'lib/active_support/values/time_zone.rb', line 290

def name
  @name
end

#tzinfoObject (readonly)

Returns the value of attribute tzinfo.



291
292
293
# File 'lib/active_support/values/time_zone.rb', line 291

def tzinfo
  @tzinfo
end

Class Method Details

.[](arg) ⇒ Object

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.



230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
# File 'lib/active_support/values/time_zone.rb', line 230

def [](arg)
  case arg
  when String
    begin
      @lazy_zones_map[arg] ||= create(arg)
    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

.allObject

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.



221
222
223
# File 'lib/active_support/values/time_zone.rb', line 221

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

.clearObject

:nodoc:



259
260
261
262
263
264
# File 'lib/active_support/values/time_zone.rb', line 259

def clear #:nodoc:
  @lazy_zones_map = Concurrent::Map.new
  @country_zones  = Concurrent::Map.new
  @zones = nil
  @zones_map = nil
end

.country_zones(country_code) ⇒ Object

A convenience method for returning a collection of TimeZone objects for time zones in the country specified by its ISO 3166-1 Alpha2 code.



254
255
256
257
# File 'lib/active_support/values/time_zone.rb', line 254

def country_zones(country_code)
  code = country_code.to_s.upcase
  @country_zones[code] ||= load_country_zones(code)
end

.createObject



209
# File 'lib/active_support/values/time_zone.rb', line 209

alias_method :create, :new

.find_tzinfo(name) ⇒ Object



205
206
207
# File 'lib/active_support/values/time_zone.rb', line 205

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

.new(name) ⇒ Object

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.)



214
215
216
# File 'lib/active_support/values/time_zone.rb', line 214

def new(name)
  self[name]
end

.seconds_to_utc_offset(seconds, colon = true) ⇒ Object

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

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


197
198
199
200
201
202
203
# File 'lib/active_support/values/time_zone.rb', line 197

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_zonesObject

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



248
249
250
# File 'lib/active_support/values/time_zone.rb', line 248

def us_zones
  country_zones(:us)
end

Instance Method Details

#<=>(zone) ⇒ Object

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



324
325
326
327
328
329
# File 'lib/active_support/values/time_zone.rb', line 324

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) ⇒ Object

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



333
334
335
# File 'lib/active_support/values/time_zone.rb', line 333

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

#at(*args) ⇒ Object

Method for creating new ActiveSupport::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

A second argument can be supplied to specify sub-second precision.

Time.zone = 'Hawaii'                # => "Hawaii"
Time.at(946684800, 123456.789).nsec # => 123456789


363
364
365
# File 'lib/active_support/values/time_zone.rb', line 363

def at(*args)
  Time.at(*args).utc.in_time_zone(self)
end

#encode_with(coder) ⇒ Object

:nodoc:



535
536
537
538
# File 'lib/active_support/values/time_zone.rb', line 535

def encode_with(coder) #:nodoc:
  coder.tag = "!ruby/object:#{self.class}"
  coder.map = { "name" => tzinfo.name }
end

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

Returns a formatted string of the offset from UTC, or an alternative string if the time zone is already UTC.

zone = ActiveSupport::TimeZone['Central Time (US & Canada)']
zone.formatted_offset        # => "-06:00"
zone.formatted_offset(false) # => "-0600"


318
319
320
# File 'lib/active_support/values/time_zone.rb', line 318

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

#init_with(coder) ⇒ Object

:nodoc:



531
532
533
# File 'lib/active_support/values/time_zone.rb', line 531

def init_with(coder) #:nodoc:
  initialize(coder["name"])
end

#iso8601(str) ⇒ Object

Method for creating new ActiveSupport::TimeWithZone instance in time zone of self from an ISO 8601 string.

Time.zone = 'Hawaii'                     # => "Hawaii"
Time.zone.iso8601('1999-12-31T14:00:00') # => Fri, 31 Dec 1999 14:00:00 HST -10:00

If the time components are missing then they will be set to zero.

Time.zone = 'Hawaii'            # => "Hawaii"
Time.zone.iso8601('1999-12-31') # => Fri, 31 Dec 1999 00:00:00 HST -10:00

If the string is invalid then an ArgumentError will be raised unlike parse which usually returns nil when given an invalid date string.

Raises:

  • (ArgumentError)


380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
# File 'lib/active_support/values/time_zone.rb', line 380

def iso8601(str)
  parts = Date._iso8601(str)

  raise ArgumentError, "invalid date" if parts.empty?

  time = Time.new(
    parts.fetch(:year),
    parts.fetch(:mon),
    parts.fetch(:mday),
    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

#local(*args) ⇒ Object

Method for creating new ActiveSupport::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


347
348
349
350
# File 'lib/active_support/values/time_zone.rb', line 347

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

#local_to_utc(time, dst = true) ⇒ Object

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



511
512
513
# File 'lib/active_support/values/time_zone.rb', line 511

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

#nowObject

Returns an ActiveSupport::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


483
484
485
# File 'lib/active_support/values/time_zone.rb', line 483

def now
  time_now.utc.in_time_zone(self)
end

#parse(str, now = now()) ⇒ Object

Method for creating new ActiveSupport::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 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

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

If the string is invalid then an ArgumentError could be raised.



420
421
422
# File 'lib/active_support/values/time_zone.rb', line 420

def parse(str, now = now())
  parts_to_time(Date._parse(str, false), now)
end

#period_for_local(time, dst = true) ⇒ Object

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



523
524
525
# File 'lib/active_support/values/time_zone.rb', line 523

def period_for_local(time, dst = true)
  tzinfo.period_for_local(time, dst) { |periods| periods.last }
end

#period_for_utc(time) ⇒ Object

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



517
518
519
# File 'lib/active_support/values/time_zone.rb', line 517

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

#periods_for_local(time) ⇒ Object

:nodoc:



527
528
529
# File 'lib/active_support/values/time_zone.rb', line 527

def periods_for_local(time) #:nodoc:
  tzinfo.periods_for_local(time)
end

#rfc3339(str) ⇒ Object

Method for creating new ActiveSupport::TimeWithZone instance in time zone of self from an RFC 3339 string.

Time.zone = 'Hawaii'                     # => "Hawaii"
Time.zone.rfc3339('2000-01-01T00:00:00Z') # => Fri, 31 Dec 1999 14:00:00 HST -10:00

If the time or zone components are missing then an ArgumentError will be raised. This is much stricter than either parse or iso8601 which allow for missing components.

Time.zone = 'Hawaii'            # => "Hawaii"
Time.zone.rfc3339('1999-12-31') # => ArgumentError: invalid date

Raises:

  • (ArgumentError)


436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
# File 'lib/active_support/values/time_zone.rb', line 436

def rfc3339(str)
  parts = Date._rfc3339(str)

  raise ArgumentError, "invalid date" if parts.empty?

  time = Time.new(
    parts.fetch(:year),
    parts.fetch(:mon),
    parts.fetch(:mday),
    parts.fetch(:hour),
    parts.fetch(:min),
    parts.fetch(:sec) + parts.fetch(:sec_fraction, 0),
    parts.fetch(:offset)
  )

  TimeWithZone.new(time.utc, self)
end

#strptime(str, format, now = now()) ⇒ Object

Parses str according to format and returns an ActiveSupport::TimeWithZone.

Assumes that str is a time in the time zone self, unless format includes an explicit time zone. (This is the same behavior as parse.) In either case, the returned TimeWithZone has the timezone of self.

Time.zone = 'Hawaii'                   # => "Hawaii"
Time.zone.strptime('1999-12-31 14:00:00', '%Y-%m-%d %H:%M:%S') # => 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.strptime('22:30:00', '%H:%M:%S') # => 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.strptime('Mar 2000', '%b %Y') # => Wed, 01 Mar 2000 00:00:00 HST -10:00


474
475
476
# File 'lib/active_support/values/time_zone.rb', line 474

def strptime(str, format, now = now())
  parts_to_time(DateTime._strptime(str, format), now)
end

#to_sObject

Returns a textual representation of this time zone.



338
339
340
# File 'lib/active_support/values/time_zone.rb', line 338

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

#todayObject

Returns the current date in this time zone.



488
489
490
# File 'lib/active_support/values/time_zone.rb', line 488

def today
  tzinfo.now.to_date
end

#tomorrowObject

Returns the next date in this time zone.



493
494
495
# File 'lib/active_support/values/time_zone.rb', line 493

def tomorrow
  today + 1
end

#utc_offsetObject

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



304
305
306
307
308
309
310
# File 'lib/active_support/values/time_zone.rb', line 304

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) ⇒ Object

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.



505
506
507
# File 'lib/active_support/values/time_zone.rb', line 505

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

#yesterdayObject

Returns the previous date in this time zone.



498
499
500
# File 'lib/active_support/values/time_zone.rb', line 498

def yesterday
  today - 1
end