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      # => #<ActiveSupport::TimeZone:0x514834...>
Time.zone.name # => "Eastern Time (US & Canada)"
Time.zone.now  # => Sun, 18 May 2008 14:30:44 EDT -04:00

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 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
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 221
def all
  @zones ||= zones_map.values.sort
end
country_zones(country_code) click to toggle source

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

# 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
create(name)
Alias for: new
find_tzinfo(name) click to toggle source
# File lib/active_support/values/time_zone.rb, line 205
def find_tzinfo(name)
  TZInfo::Timezone.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 214
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 297
def initialize(name, utc_offset = nil, tzinfo = nil)
  @name = name
  @utc_offset = utc_offset
  @tzinfo = tzinfo || TimeZone.find_tzinfo(name)
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.

ActiveSupport::TimeZone.seconds_to_utc_offset(-21_600) # => "-06:00"
# 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_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 248
def us_zones
  country_zones(:us)
end

Private Class Methods

load_country_zones(code) click to toggle source
# File lib/active_support/values/time_zone.rb, line 267
def load_country_zones(code)
  country = TZInfo::Country.get(code)
  country.zone_identifiers.map do |tz_id|
    if MAPPING.value?(tz_id)
      MAPPING.inject([]) do |memo, (key, value)|
        memo << self[key] if value == tz_id
        memo
      end
    else
      create(tz_id, nil, TZInfo::Timezone.new(tz_id))
    end
  end.flatten(1).sort!
end
zones_map() click to toggle source
# File lib/active_support/values/time_zone.rb, line 281
def zones_map
  @zones_map ||= MAPPING.each_with_object({}) do |(name, _), zones|
    timezone = self[name]
    zones[name] = timezone if timezone
  end
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 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) 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 333
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 358
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 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"
# 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
iso8601(str) click to toggle source

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.

# File lib/active_support/values/time_zone.rb, line 375
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) 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 347
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 506
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 478
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

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

# File lib/active_support/values/time_zone.rb, line 415
def parse(str, now = now())
  parts_to_time(Date._parse(str, false), now)
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 518
def period_for_local(time, dst = true)
  tzinfo.period_for_local(time, dst) { |periods| periods.last }
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 512
def period_for_utc(time)
  tzinfo.period_for_utc(time)
end
rfc3339(str) click to toggle source

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
# File lib/active_support/values/time_zone.rb, line 431
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()) click to toggle source

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 #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
# File lib/active_support/values/time_zone.rb, line 469
def strptime(str, format, now = now())
  parts_to_time(DateTime._strptime(str, format), now)
end
to_s() click to toggle source

Returns a textual representation of this time zone.

# File lib/active_support/values/time_zone.rb, line 338
def to_s
  "(GMT#{formatted_offset}) #{name}"
end
today() click to toggle source

Returns the current date in this time zone.

# File lib/active_support/values/time_zone.rb, line 483
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 488
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 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) 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 500
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 493
def yesterday
  today - 1
end

Private Instance Methods

parts_to_time(parts, now) click to toggle source
# File lib/active_support/values/time_zone.rb, line 536
def parts_to_time(parts, now)
  raise ArgumentError, "invalid date" if parts.nil?
  return if parts.empty?

  if parts[:seconds]
    time = Time.at(parts[:seconds])
  else
    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)
    )
  end

  if parts[:offset] || parts[:seconds]
    TimeWithZone.new(time.utc, self)
  else
    TimeWithZone.new(nil, self, time)
  end
end
time_now() click to toggle source
# File lib/active_support/values/time_zone.rb, line 561
def time_now
  Time.now
end