class ActiveSupport::TimeZone

The TimeZone class serves as a wrapper around TZInfo::Timezone instances. It allows us to do the following:

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.)

Constants

MAPPING

Keys are Rails TimeZone names, values are TZInfo identifiers.

UTC_OFFSET_WITHOUT_COLON
UTC_OFFSET_WITH_COLON

Attributes

name[R]
tzinfo[R]

Public Class Methods

[](arg) click to toggle source

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
all() click to toggle source

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.

# File lib/active_support/values/time_zone.rb, line 223
def all
  @zones ||= zones_map.values.sort
end
create(name)
Alias for: new
find_tzinfo(name) click to toggle source
# File lib/active_support/values/time_zone.rb, line 207
def find_tzinfo(name)
  TZInfo::TimezoneProxy.new(MAPPING[name] || name)
end
new(name) click to toggle source

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
Also aliased as: create
new(name, utc_offset = nil, tzinfo = nil) click to toggle source

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
seconds_to_utc_offset(seconds, colon = true) click to toggle source

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
us_zones() click to toggle source

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

Public Instance Methods

<=>(zone) click to toggle source

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
=~(re) click to toggle source

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
at(secs) click to toggle source

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
formatted_offset(colon=true, alternate_utc_string = nil) click to toggle source

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
local(*args) click to toggle source

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
local_to_utc(time, dst=true) click to toggle source

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
now() click to toggle source

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
parse(str, now=now()) click to toggle source

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
period_for_local(time, dst=true) click to toggle source

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
period_for_utc(time) click to toggle source

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
to_s() click to toggle source

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
today() click to toggle source

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
tomorrow() click to toggle source

Returns the next date in this time zone.

# File lib/active_support/values/time_zone.rb, line 385
def tomorrow
  today + 1
end
utc_offset() click to toggle source

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
utc_to_local(time) click to toggle source

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
yesterday() click to toggle source

Returns the previous date in this time zone.

# File lib/active_support/values/time_zone.rb, line 390
def yesterday
  today - 1
end

Private Instance Methods

time_now() click to toggle source
# File lib/active_support/values/time_zone.rb, line 424
def time_now
  Time.now
end