class ActiveSupport::TimeZone

Active Support Time Zone

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 134 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      # => #<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.

Public Class Methods

[] (arg)

Source

# File lib/active_support/values/time_zone.rb, line 232
def [](arg)
  case arg
  when self
    arg
  when String
    begin
      @lazy_zones_map[arg] ||= create(arg)
    rescue TZInfo::InvalidTimezoneIdentifier
      nil
    end
  when TZInfo::Timezone
    @lazy_zones_map[arg.name] ||= create(arg.name, nil, arg)
  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

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.

all ()

Source

# File lib/active_support/values/time_zone.rb, line 223
def all
  @zones ||= zones_map.values.sort
end

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.

country_zones (country_code)

Source

# File lib/active_support/values/time_zone.rb, line 260
def country_zones(country_code)
  code = country_code.to_s.upcase
  @country_zones[code] ||= load_country_zones(code)
end

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

create(name, utc_offset = nil, tzinfo = nil)

Source

# File lib/active_support/values/time_zone.rb, line 300

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).

find_tzinfo (name)

Source

# File lib/active_support/values/time_zone.rb, line 207
def find_tzinfo(name)
  TZInfo::Timezone.get(MAPPING[name] || name)
end

new (name)

Source

# File lib/active_support/values/time_zone.rb, line 216
def new(name)
  self[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.)

seconds_to_utc_offset (seconds, colon = true)

Source

# 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

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"

us_zones ()

Source

# File lib/active_support/values/time_zone.rb, line 254
def us_zones
  country_zones(:us)
end

A convenience method for returning a collection of TimeZone objects for time zones in the USA.

Private Class Methods

load_country_zones (code)

Source

# File lib/active_support/values/time_zone.rb, line 273
def load_country_zones(code)
  country = TZInfo::Country.get(code)
  country.zone_identifiers.flat_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.get(tz_id))
    end
  end.sort!
end

zones_map ()

Source

# File lib/active_support/values/time_zone.rb, line 287
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)

Source

# File lib/active_support/values/time_zone.rb, line 333
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 this time zone to the parameter. The two are compared first on their offsets, and then by name.

=~ (re)

Source

# File lib/active_support/values/time_zone.rb, line 342
def =~(re)
  re === name || re === MAPPING[name]
end

Compare name and TZInfo identifier to a supplied regexp, returning true if a match is found.

at (*args)

Source

# File lib/active_support/values/time_zone.rb, line 379
def at(*args)
  Time.at(*args).utc.in_time_zone(self)
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

A second argument can be supplied to specify sub-second precision.

Time.zone = 'Hawaii'                # => "Hawaii"
Time.at(946684800, 123456.789).nsec # => 123456789

formatted_offset (colon = true, alternate_utc_string = nil)

Source

# File lib/active_support/values/time_zone.rb, line 327
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

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"

iso8601 (str)

Source

# File lib/active_support/values/time_zone.rb, line 396
def iso8601(str)
  # Historically `Date._iso8601(nil)` returns `{}`, but in the `date` gem versions `3.2.1`, `3.1.2`, `3.0.2`,
  # and `2.0.1`, `Date._iso8601(nil)` raises `TypeError` https://github.com/ruby/date/issues/39
  # Future `date` releases are expected to revert back to the original behavior.
  raise ArgumentError, "invalid date" if str.nil?

  parts = Date._iso8601(str)

  year = parts.fetch(:year)

  if parts.key?(:yday)
    ordinal_date = Date.ordinal(year, parts.fetch(:yday))
    month = ordinal_date.month
    day = ordinal_date.day
  else
    month = parts.fetch(:mon)
    day = parts.fetch(:mday)
  end

  time = Time.new(
    year,
    month,
    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

rescue Date::Error, KeyError
  raise ArgumentError, "invalid date"
end

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.

local (*args)

Source

# File lib/active_support/values/time_zone.rb, line 363
def local(*args)
  time = Time.utc(*args)
  ActiveSupport::TimeWithZone.new(nil, self, time)
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

local_to_utc (time, dst = true)

Source

# File lib/active_support/values/time_zone.rb, line 551
def local_to_utc(time, dst = true)
  tzinfo.local_to_utc(time, dst)
end

Adjust the given time to the simultaneous time in UTC. Returns a Time.utc() instance.

match? (re)

Source

# File lib/active_support/values/time_zone.rb, line 348
def match?(re)
  (re == name) || (re == MAPPING[name]) ||
    ((Regexp === re) && (re.match?(name) || re.match?(MAPPING[name])))
end

Compare name and TZInfo identifier to a supplied regexp, returning true if a match is found.

now ()

Source

# File lib/active_support/values/time_zone.rb, line 516
def now
  time_now.utc.in_time_zone(self)
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

parse (str, now = now())

Source

# File lib/active_support/values/time_zone.rb, line 453
def parse(str, now = now())
  parts_to_time(Date._parse(str, false), now)
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 TimeZone#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.

rfc3339 (str)

Source

# File lib/active_support/values/time_zone.rb, line 469
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

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

strptime (str, format, now = now())

Source

# File lib/active_support/values/time_zone.rb, line 507
def strptime(str, format, now = now())
  parts_to_time(DateTime._strptime(str, format), now)
end

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 TimeZone#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

to_s ()

Source

# File lib/active_support/values/time_zone.rb, line 354
def to_s
  "(GMT#{formatted_offset}) #{name}"
end

Returns a textual representation of this time zone.

today ()

Source

# File lib/active_support/values/time_zone.rb, line 521
def today
  tzinfo.now.to_date
end

Returns the current date in this time zone.

tomorrow ()

Source

# File lib/active_support/values/time_zone.rb, line 526
def tomorrow
  today + 1
end

Returns the next date in this time zone.

utc_offset ()

Source

# File lib/active_support/values/time_zone.rb, line 317
def utc_offset
  @utc_offset || tzinfo&.current_period&.base_utc_offset
end

Returns the offset of this time zone from UTC in seconds.

utc_to_local (time)

Source

# File lib/active_support/values/time_zone.rb, line 542
def utc_to_local(time)
  tzinfo.utc_to_local(time).yield_self do |t|
    ActiveSupport.utc_to_local_returns_utc_offset_times ?
      t : Time.utc(t.year, t.month, t.day, t.hour, t.min, t.sec, t.sec_fraction * 1_000_000)
  end
end

Adjust the given time to the simultaneous time in the time zone represented by self. Returns a local time with the appropriate offset – if you want an ActiveSupport::TimeWithZone instance, use Time#in_time_zone() instead.

As of tzinfo 2, utc_to_local returns a Time with a non-zero utc_offset. See the utc_to_local_returns_utc_offset_times config for more info.

yesterday ()

Source

# File lib/active_support/values/time_zone.rb, line 531
def yesterday
  today - 1
end

Returns the previous date in this time zone.

Private Instance Methods

parts_to_time (parts, now)

Source

# File lib/active_support/values/time_zone.rb, line 585
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 ()

Source

# File lib/active_support/values/time_zone.rb, line 610
def time_now
  Time.now
end