2 # Copyright (c) 2005-2006 Philip Ross
4 # Permission is hereby granted, free of charge, to any person obtaining a copy
5 # of this software and associated documentation files (the "Software"), to deal
6 # in the Software without restriction, including without limitation the rights
7 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 # copies of the Software, and to permit persons to whom the Software is
9 # furnished to do so, subject to the following conditions:
11 # The above copyright notice and this permission notice shall be included in all
12 # copies or substantial portions of the Software.
14 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 # require 'tzinfo/country'
25 require 'tzinfo/time_or_datetime'
26 require 'tzinfo/timezone_period'
29 # Indicate a specified time in a local timezone has more than one
30 # possible time in UTC. This happens when switching from daylight savings time
31 # to normal time where the clocks are rolled back. Thrown by period_for_local
32 # and local_to_utc when using an ambiguous time and not specifying any
33 # means to resolve the ambiguity.
34 class AmbiguousTime
< StandardError
37 # Thrown to indicate that no TimezonePeriod matching a given time could be found.
38 class PeriodNotFound
< StandardError
41 # Thrown by Timezone#get if the identifier given is not valid.
42 class InvalidTimezoneIdentifier
< StandardError
45 # Thrown if an attempt is made to use a timezone created with Timezone.new(nil).
46 class UnknownTimezone
< StandardError
49 # Timezone is the base class of all timezones. It provides a factory method
50 # get to access timezones by identifier. Once a specific Timezone has been
51 # retrieved, DateTimes, Times and timestamps can be converted between the UTC
52 # and the local time for the zone. For example:
54 # tz = TZInfo::Timezone.get('America/New_York')
55 # puts tz.utc_to_local(DateTime.new(2005,8,29,15,35,0)).to_s
56 # puts tz.local_to_utc(Time.utc(2005,8,29,11,35,0)).to_s
57 # puts tz.utc_to_local(1125315300).to_s
59 # Each time conversion method returns an object of the same type it was
62 # The timezone information all comes from the tz database
63 # (see http://www.twinsun.com/tz/tz-link.htm)
67 # Cache of loaded zones by identifier to avoid using require if a zone
68 # has already been loaded.
71 # Whether the timezones index has been loaded yet.
72 @
@index_loaded = false
74 # Returns a timezone by its identifier (e.g. "Europe/London",
75 # "America/Chicago" or "UTC").
77 # Raises InvalidTimezoneIdentifier if the timezone couldn't be found.
78 def self.get(identifier
)
79 instance
= @
@loaded_zones[identifier
]
81 raise InvalidTimezoneIdentifier
, 'Invalid identifier' if identifier
!~
/^[A-z0-9\+\-_]+(\/[A-z0-9\
+\
-_
]+)*$/
82 identifier
= identifier
.gsub(/-/, '__m__').gsub(/\+/, '__p__')
84 # Use a temporary variable to avoid an rdoc warning
85 file
= "tzinfo/definitions/#{identifier}"
89 identifier
.split(/\//).each
{|part
|
95 # Could make Timezone subclasses register an interest in an info
96 # type. Since there are currently only two however, there isn't
98 if info
.kind_of
?(DataTimezoneInfo
)
99 instance
= DataTimezone
.new(info
)
100 elsif info
.kind_of
?(LinkedTimezoneInfo
)
101 instance
= LinkedTimezone
.new(info
)
103 raise InvalidTimezoneIdentifier
, "No handler for info type #{info.class}"
106 @
@loaded_zones[instance
.identifier
] = instance
107 rescue LoadError
, NameError
=> e
108 raise InvalidTimezoneIdentifier
, e
.message
115 # Returns a proxy for the Timezone with the given identifier. The proxy
116 # will cause the real timezone to be loaded when an attempt is made to
117 # find a period or convert a time. get_proxy will not validate the
118 # identifier. If an invalid identifier is specified, no exception will be
119 # raised until the proxy is used.
120 def self.get_proxy(identifier
)
121 TimezoneProxy
.new(identifier
)
124 # If identifier is nil calls super(), otherwise calls get. An identfier
125 # should always be passed in when called externally.
126 def self.new(identifier
= nil)
134 # Returns an array containing all the available Timezones.
136 # Returns TimezoneProxy objects to avoid the overhead of loading Timezone
137 # definitions until a conversion is actually required.
139 get_proxies(all_identifiers
)
142 # Returns an array containing the identifiers of all the available
144 def self.all_identifiers
146 Indexes
::Timezones.timezones
149 # Returns an array containing all the available Timezones that are based
150 # on data (are not links to other Timezones).
152 # Returns TimezoneProxy objects to avoid the overhead of loading Timezone
153 # definitions until a conversion is actually required.
154 def self.all_data_zones
155 get_proxies(all_data_zone_identifiers
)
158 # Returns an array containing the identifiers of all the available
159 # Timezones that are based on data (are not links to other Timezones)..
160 def self.all_data_zone_identifiers
162 Indexes
::Timezones.data_timezones
165 # Returns an array containing all the available Timezones that are links
166 # to other Timezones.
168 # Returns TimezoneProxy objects to avoid the overhead of loading Timezone
169 # definitions until a conversion is actually required.
170 def self.all_linked_zones
171 get_proxies(all_linked_zone_identifiers
)
174 # Returns an array containing the identifiers of all the available
175 # Timezones that are links to other Timezones.
176 def self.all_linked_zone_identifiers
178 Indexes
::Timezones.linked_timezones
181 # Returns all the Timezones defined for all Countries. This is not the
182 # complete set of Timezones as some are not country specific (e.g.
185 # Returns TimezoneProxy objects to avoid the overhead of loading Timezone
186 # definitions until a conversion is actually required.
187 def self.all_country_zones
188 Country
.all_codes
.inject([]) {|zones
,country
|
189 zones
+= Country
.get(country
).zones
193 # Returns all the zone identifiers defined for all Countries. This is not the
194 # complete set of zone identifiers as some are not country specific (e.g.
195 # 'Etc/GMT'). You can obtain a Timezone instance for a given identifier
196 # with the get method.
197 def self.all_country_zone_identifiers
198 Country
.all_codes
.inject([]) {|zones
,country
|
199 zones
+= Country
.get(country
).zone_identifiers
203 # Returns all US Timezone instances. A shortcut for
204 # TZInfo::Country.get('US').zones.
206 # Returns TimezoneProxy objects to avoid the overhead of loading Timezone
207 # definitions until a conversion is actually required.
209 Country
.get('US').zones
212 # Returns all US zone identifiers. A shortcut for
213 # TZInfo::Country.get('US').zone_identifiers.
214 def self.us_zone_identifiers
215 Country
.get('US').zone_identifiers
218 # The identifier of the timezone, e.g. "Europe/Paris".
220 raise UnknownTimezone
, 'TZInfo::Timezone constructed directly'
223 # An alias for identifier.
225 # Don't use alias, as identifier gets overridden.
229 # Returns a friendlier version of the identifier.
234 # Returns internal object state as a programmer-readable string.
236 "#<#{self.class}: #{identifier}>"
239 # Returns a friendlier version of the identifier. Set skip_first_part to
240 # omit the first part of the identifier (typically a region name) where
241 # there is more than one part.
245 # Timezone.get('Europe/Paris').friendly_identifier(false) #=> "Europe - Paris"
246 # Timezone.get('Europe/Paris').friendly_identifier(true) #=> "Paris"
247 # Timezone.get('America/Indiana/Knox').friendly_identifier(false) #=> "America - Knox, Indiana"
248 # Timezone.get('America/Indiana/Knox').friendly_identifier(true) #=> "Knox, Indiana"
249 def friendly_identifier(skip_first_part
= false)
250 parts
= identifier
.split('/')
254 elsif parts
.length
== 1
260 result
= parts
[0] + ' - '
263 parts
[1, parts
.length
- 1].reverse_each
{|part
|
266 if part
.index(/[a-z]/)
267 # Missing a space if a lower case followed by an upper case and the
269 part
.gsub
!(/([^M][a-z])([A-Z])/, '\1 \2')
270 part
.gsub
!(/([M][a-bd-z])([A-Z])/, '\1 \2')
272 # Missing an apostrophe if two consecutive upper case characters.
273 part
.gsub
!(/([A-Z])([A-Z])/, '\1\'\2')
280 result
.slice
!(result
.length
- 2, 2)
285 # Returns the TimezonePeriod for the given UTC time. utc can either be
286 # a DateTime, Time or integer timestamp (Time.to_i). Any timezone
287 # information in utc is ignored (it is treated as a UTC time).
288 def period_for_utc(utc
)
289 raise UnknownTimezone
, 'TZInfo::Timezone constructed directly'
292 # Returns the set of TimezonePeriod instances that are valid for the given
293 # local time as an array. If you just want a single period, use
294 # period_for_local instead and specify how ambiguities should be resolved.
295 # Returns an empty array if no periods are found for the given time.
296 def periods_for_local(local
)
297 raise UnknownTimezone
, 'TZInfo::Timezone constructed directly'
300 # Returns the TimezonePeriod for the given local time. local can either be
301 # a DateTime, Time or integer timestamp (Time.to_i). Any timezone
302 # information in local is ignored (it is treated as a time in the current
305 # Warning: There are local times that have no equivalent UTC times (e.g.
306 # in the transition from standard time to daylight savings time). There are
307 # also local times that have more than one UTC equivalent (e.g. in the
308 # transition from daylight savings time to standard time).
310 # In the first case (no equivalent UTC time), a PeriodNotFound exception
313 # In the second case (more than one equivalent UTC time), an AmbiguousTime
314 # exception will be raised unless the optional dst parameter or block
315 # handles the ambiguity.
317 # If the ambiguity is due to a transition from daylight savings time to
318 # standard time, the dst parameter can be used to select whether the
319 # daylight savings time or local time is used. For example,
321 # Timezone.get('America/New_York').period_for_local(DateTime.new(2004,10,31,1,30,0))
323 # would raise an AmbiguousTime exception.
325 # Specifying dst=true would the daylight savings period from April to
326 # October 2004. Specifying dst=false would return the standard period
327 # from October 2004 to April 2005.
329 # If the dst parameter does not resolve the ambiguity, and a block is
330 # specified, it is called. The block must take a single parameter - an
331 # array of the periods that need to be resolved. The block can select and
332 # return a single period or return nil or an empty array
333 # to cause an AmbiguousTime exception to be raised.
334 def period_for_local(local
, dst
= nil)
335 results
= periods_for_local(local
)
339 elsif results
.size
< 2
342 # ambiguous result try to resolve
345 matches
= results
.find_all
{|period
| period
.dst
? == dst
}
346 results
= matches
if !matches
.empty
?
352 # still ambiguous, try the block
355 results
= yield results
358 if results
.is_a
?(TimezonePeriod
)
360 elsif results
&& results
.size
== 1
363 raise AmbiguousTime
, "#{local} is an ambiguous local time."
369 # Converts a time in UTC to the local timezone. utc can either be
370 # a DateTime, Time or timestamp (Time.to_i). The returned time has the same
371 # type as utc. Any timezone information in utc is ignored (it is treated as
373 def utc_to_local(utc
)
374 TimeOrDateTime
.wrap(utc
) {|wrapped
|
375 period_for_utc(wrapped
).to_local(wrapped
)
379 # Converts a time in the local timezone to UTC. local can either be
380 # a DateTime, Time or timestamp (Time.to_i). The returned time has the same
381 # type as local. Any timezone information in local is ignored (it is treated
384 # Warning: There are local times that have no equivalent UTC times (e.g.
385 # in the transition from standard time to daylight savings time). There are
386 # also local times that have more than one UTC equivalent (e.g. in the
387 # transition from daylight savings time to standard time).
389 # In the first case (no equivalent UTC time), a PeriodNotFound exception
392 # In the second case (more than one equivalent UTC time), an AmbiguousTime
393 # exception will be raised unless the optional dst parameter or block
394 # handles the ambiguity.
396 # If the ambiguity is due to a transition from daylight savings time to
397 # standard time, the dst parameter can be used to select whether the
398 # daylight savings time or local time is used. For example,
400 # Timezone.get('America/New_York').local_to_utc(DateTime.new(2004,10,31,1,30,0))
402 # would raise an AmbiguousTime exception.
404 # Specifying dst=true would return 2004-10-31 5:30:00. Specifying dst=false
405 # would return 2004-10-31 6:30:00.
407 # If the dst parameter does not resolve the ambiguity, and a block is
408 # specified, it is called. The block must take a single parameter - an
409 # array of the periods that need to be resolved. The block can return a
410 # single period to use to convert the time or return nil or an empty array
411 # to cause an AmbiguousTime exception to be raised.
412 def local_to_utc(local
, dst
= nil)
413 TimeOrDateTime
.wrap(local
) {|wrapped
|
415 period
= period_for_local(wrapped
, dst
) {|periods
| yield periods
}
417 period
= period_for_local(wrapped
, dst
)
420 period
.to_utc(wrapped
)
424 # Returns the current time in the timezone as a Time.
426 utc_to_local(Time
.now
.utc
)
429 # Returns the TimezonePeriod for the current time.
431 period_for_utc(Time
.now
.utc
)
434 # Returns the current Time and TimezonePeriod as an array. The first element
435 # is the time, the second element is the period.
436 def current_period_and_time
438 period
= period_for_utc(utc
)
439 [period
.to_local(utc
), period
]
442 alias :current_time_and_period :current_period_and_time
444 # Converts a time in UTC to local time and returns it as a string
445 # according to the given format. The formatting is identical to
446 # Time.strftime and DateTime.strftime, except %Z is replaced with the
447 # timezone abbreviation for the specified time (for example, EST or EDT).
448 def strftime(format
, utc
= Time
.now
.utc
)
449 period
= period_for_utc(utc
)
450 local
= period
.to_local(utc
)
451 local
= Time
.at(local
).utc
unless local
.kind_of
?(Time
) || local
.kind_of
?(DateTime
)
452 abbreviation
= period
.abbreviation
.to_s
.gsub(/%/, '%%')
454 format
= format
.gsub(/(.?)%Z/) do
456 # return %%Z so the real strftime treats it as a literal %Z too
463 local
.strftime(format
)
466 # Compares two Timezones based on their identifier. Returns -1 if tz is less
467 # than self, 0 if tz is equal to self and +1 if tz is greater than self.
469 identifier
<=> tz
.identifier
472 # Returns true if and only if the identifier of tz is equal to the
473 # identifier of this Timezone.
478 # Returns a hash of this Timezone.
483 # Dumps this Timezone for marshalling.
488 # Loads a marshalled Timezone.
494 # Loads in the index of timezones if it hasn't already been loaded.
496 unless @
@index_loaded
497 require 'tzinfo/indexes/timezones'
498 @
@index_loaded = true
502 # Returns an array of proxies corresponding to the given array of
504 def self.get_proxies(identifiers
)
505 identifiers
.collect
{|identifier
| get_proxy(identifier
)}