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 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 # => #<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.)
Keys are Rails TimeZone names, values are TZInfo identifiers.
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.
# File lib/active_support/values/time_zone.rb, line 377 def [](arg) case arg when String begin lazy_zones_map[arg] ||= lookup(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
# File lib/active_support/values/time_zone.rb, line 342 def self.find_tzinfo(name) TZInfo::TimezoneProxy.new(MAPPING[name] || name) 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).
# File lib/active_support/values/time_zone.rb, line 207 def initialize(name, utc_offset = nil, tzinfo = nil) self.class.send(:require_tzinfo) @name = name @utc_offset = utc_offset @tzinfo = tzinfo || TimeZone.find_tzinfo(name) @current_period = nil end
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"
# File lib/active_support/values/time_zone.rb, line 191 def self.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
A convenience method for returning a collection of TimeZone objects for time zones in the USA.
# File lib/active_support/values/time_zone.rb, line 395 def us_zones @us_zones ||= all.find_all { |z| z.name =~ /US|Arizona|Indiana|Hawaii|Alaska/ } end
# File lib/active_support/values/time_zone.rb, line 363 def zones_map @zones_map ||= begin new_zones_names = MAPPING.keys - lazy_zones_map.keys new_zones = Hash[new_zones_names.map { |place| [place, create(place)] }] lazy_zones_map.merge(new_zones) end end
# File lib/active_support/values/time_zone.rb, line 401 def require_tzinfo require 'tzinfo' unless defined?(::TZInfo) rescue LoadError $stderr.puts "You don't have tzinfo installed in your application. Please add it to your Gemfile and run bundle install" raise end
# File lib/active_support/values/time_zone.rb, line 414 def lazy_zones_map require_tzinfo @lazy_zones_map ||= Hash.new do |hash, place| hash[place] = create(place) if MAPPING.has_key?(place) end end
# File lib/active_support/values/time_zone.rb, line 410 def lookup(name) (tzinfo = find_tzinfo(name)) && create(tzinfo.name.freeze) end
Compare this time zone to the parameter. The two are compared first on their offsets, and then by name.
# File lib/active_support/values/time_zone.rb, line 234 def <=>(zone) result = (utc_offset <=> zone.utc_offset) result = (name <=> zone.name) if result == 0 result end
Compare name and TZInfo
identifier to a supplied regexp, returning true
if a match is
found.
# File lib/active_support/values/time_zone.rb, line 242 def =~(re) re === name || re === MAPPING[name] end
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
# File lib/active_support/values/time_zone.rb, line 267 def at(secs) Time.at(secs).utc.in_time_zone(self) end
Returns the offset of this time zone as a formatted string, of the format “+HH:MM”.
# File lib/active_support/values/time_zone.rb, line 228 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
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
# File lib/active_support/values/time_zone.rb, line 256 def local(*args) time = Time.utc(*args) ActiveSupport::TimeWithZone.new(nil, self, time) end
Adjust the given time to the simultaneous time in UTC. Returns a Time.utc() instance.
# File lib/active_support/values/time_zone.rb, line 326 def local_to_utc(time, dst=true) tzinfo.local_to_utc(time, dst) end
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
# File lib/active_support/values/time_zone.rb, line 308 def now time_now.utc.in_time_zone(self) end
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 #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
# File lib/active_support/values/time_zone.rb, line 282 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, 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
Available so that TimeZone instances respond like TZInfo::Timezone instances.
# File lib/active_support/values/time_zone.rb, line 338 def period_for_local(time, dst=true) tzinfo.period_for_local(time, dst) end
Available so that TimeZone instances respond like TZInfo::Timezone instances.
# File lib/active_support/values/time_zone.rb, line 332 def period_for_utc(time) tzinfo.period_for_utc(time) end
Returns a textual representation of this time zone.
# File lib/active_support/values/time_zone.rb, line 247 def to_s "(GMT#{formatted_offset}) #{name}" end
Return the current date in this time zone.
# File lib/active_support/values/time_zone.rb, line 313 def today tzinfo.now.to_date end
Returns the offset of this time zone from UTC in seconds.
# File lib/active_support/values/time_zone.rb, line 217 def utc_offset if @utc_offset @utc_offset else @current_period ||= tzinfo.try(:current_period) @current_period.try(:utc_offset) end 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.
# File lib/active_support/values/time_zone.rb, line 320 def utc_to_local(time) tzinfo.utc_to_local(time) end
# File lib/active_support/values/time_zone.rb, line 425 def time_now Time.now end