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 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
# File lib/active_support/values/time_zone.rb, line 207 def find_tzinfo(name) TZInfo::TimezoneProxy.new(MAPPING[name] || name) end
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.)
# File lib/active_support/values/time_zone.rb, line 216 def new(name) self[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 270 def initialize(name, utc_offset = nil, tzinfo = nil) @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 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
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 257 def us_zones @us_zones ||= all.find_all { |z| z.name =~ /US|Arizona|Indiana|Hawaii|Alaska/ } 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 295 def <=>(zone) return unless zone.respond_to? :utc_offset 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 304 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 329 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 289 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 318 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 403 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 375 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
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
# File lib/active_support/values/time_zone.rb, line 349 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
Available so that TimeZone instances respond like TZInfo::Timezone instances.
# File lib/active_support/values/time_zone.rb, line 415 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 409 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 309 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 380 def today tzinfo.now.to_date end
Returns the next date in this time zone.
# File lib/active_support/values/time_zone.rb, line 385 def tomorrow today + 1 end
Returns the offset of this time zone from UTC in seconds.
# File lib/active_support/values/time_zone.rb, line 278 def utc_offset if @utc_offset @utc_offset else @current_period ||= tzinfo.current_period if tzinfo @current_period.utc_offset if @current_period 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 DateAndTime::Zones#in_time_zone
instead.
# File lib/active_support/values/time_zone.rb, line 397 def utc_to_local(time) tzinfo.utc_to_local(time) end
Returns the previous date in this time zone.
# File lib/active_support/values/time_zone.rb, line 390 def yesterday today - 1 end
# File lib/active_support/values/time_zone.rb, line 424 def time_now Time.now end