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

Inherits From

module Comparable

Constants

`MAPPING`

Keys are Rails TimeZone names, values are TZInfo identifiers.

{
"International Date Line West" => "Etc/GMT+12",
"Midway Island"                => "Pacific/Midway",
"American Samoa"               => "Pacific/Pago_Pago",
"Hawaii"                       => "Pacific/Honolulu",
"Alaska"                       => "America/Juneau",
"Pacific Time (US & Canada)"   => "America/Los_Angeles",
"Tijuana"                      => "America/Tijuana",
"Mountain Time (US & Canada)"  => "America/Denver",
"Arizona"                      => "America/Phoenix",
"Chihuahua"                    => "America/Chihuahua",
"Mazatlan"                     => "America/Mazatlan",
"Central Time (US & Canada)"   => "America/Chicago",
"Saskatchewan"                 => "America/Regina",
"Guadalajara"                  => "America/Mexico_City",
"Mexico City"                  => "America/Mexico_City",
"Monterrey"                    => "America/Monterrey",
"Central America"              => "America/Guatemala",
"Eastern Time (US & Canada)"   => "America/New_York",
"Indiana (East)"               => "America/Indiana/Indianapolis",
"Bogota"                       => "America/Bogota",
"Lima"                         => "America/Lima",
"Quito"                        => "America/Lima",
"Atlantic Time (Canada)"       => "America/Halifax",
"Caracas"                      => "America/Caracas",
"La Paz"                       => "America/La_Paz",
"Santiago"                     => "America/Santiago",
"Newfoundland"                 => "America/St_Johns",
"Brasilia"                     => "America/Sao_Paulo",
"Buenos Aires"                 => "America/Argentina/Buenos_Aires",
"Montevideo"                   => "America/Montevideo",
"Georgetown"                   => "America/Guyana",
"Puerto Rico"                  => "America/Puerto_Rico",
"Greenland"                    => "America/Godthab",
"Mid-Atlantic"                 => "Atlantic/South_Georgia",
"Azores"                       => "Atlantic/Azores",
"Cape Verde Is."               => "Atlantic/Cape_Verde",
"Dublin"                       => "Europe/Dublin",
"Edinburgh"                    => "Europe/London",
"Lisbon"                       => "Europe/Lisbon",
"London"                       => "Europe/London",
"Casablanca"                   => "Africa/Casablanca",
"Monrovia"                     => "Africa/Monrovia",
"UTC"                          => "Etc/UTC",
"Belgrade"                     => "Europe/Belgrade",
"Bratislava"                   => "Europe/Bratislava",
"Budapest"                     => "Europe/Budapest",
"Ljubljana"                    => "Europe/Ljubljana",
"Prague"                       => "Europe/Prague",
"Sarajevo"                     => "Europe/Sarajevo",
"Skopje"                       => "Europe/Skopje",
"Warsaw"                       => "Europe/Warsaw",
"Zagreb"                       => "Europe/Zagreb",
"Brussels"                     => "Europe/Brussels",
"Copenhagen"                   => "Europe/Copenhagen",
"Madrid"                       => "Europe/Madrid",
"Paris"                        => "Europe/Paris",
"Amsterdam"                    => "Europe/Amsterdam",
"Berlin"                       => "Europe/Berlin",
"Bern"                         => "Europe/Zurich",
"Zurich"                       => "Europe/Zurich",
"Rome"                         => "Europe/Rome",
"Stockholm"                    => "Europe/Stockholm",
"Vienna"                       => "Europe/Vienna",
"West Central Africa"          => "Africa/Algiers",
"Bucharest"                    => "Europe/Bucharest",
"Cairo"                        => "Africa/Cairo",
"Helsinki"                     => "Europe/Helsinki",
"Kyiv"                         => "Europe/Kiev",
"Riga"                         => "Europe/Riga",
"Sofia"                        => "Europe/Sofia",
"Tallinn"                      => "Europe/Tallinn",
"Vilnius"                      => "Europe/Vilnius",
"Athens"                       => "Europe/Athens",
"Istanbul"                     => "Europe/Istanbul",
"Minsk"                        => "Europe/Minsk",
"Jerusalem"                    => "Asia/Jerusalem",
"Harare"                       => "Africa/Harare",
"Pretoria"                     => "Africa/Johannesburg",
"Kaliningrad"                  => "Europe/Kaliningrad",
"Moscow"                       => "Europe/Moscow",
"St. Petersburg"               => "Europe/Moscow",
"Volgograd"                    => "Europe/Volgograd",
"Samara"                       => "Europe/Samara",
"Kuwait"                       => "Asia/Kuwait",
"Riyadh"                       => "Asia/Riyadh",
"Nairobi"                      => "Africa/Nairobi",
"Baghdad"                      => "Asia/Baghdad",
"Tehran"                       => "Asia/Tehran",
"Abu Dhabi"                    => "Asia/Muscat",
"Muscat"                       => "Asia/Muscat",
"Baku"                         => "Asia/Baku",
"Tbilisi"                      => "Asia/Tbilisi",
"Yerevan"                      => "Asia/Yerevan",
"Kabul"                        => "Asia/Kabul",
"Ekaterinburg"                 => "Asia/Yekaterinburg",
"Islamabad"                    => "Asia/Karachi",
"Karachi"                      => "Asia/Karachi",
"Tashkent"                     => "Asia/Tashkent",
"Chennai"                      => "Asia/Kolkata",
"Kolkata"                      => "Asia/Kolkata",
"Mumbai"                       => "Asia/Kolkata",
"New Delhi"                    => "Asia/Kolkata",
"Kathmandu"                    => "Asia/Kathmandu",
"Dhaka"                        => "Asia/Dhaka",
"Sri Jayawardenepura"          => "Asia/Colombo",
"Almaty"                       => "Asia/Almaty",
"Astana"                       => "Asia/Almaty",
"Novosibirsk"                  => "Asia/Novosibirsk",
"Rangoon"                      => "Asia/Rangoon",
"Bangkok"                      => "Asia/Bangkok",
"Hanoi"                        => "Asia/Bangkok",
"Jakarta"                      => "Asia/Jakarta",
"Krasnoyarsk"                  => "Asia/Krasnoyarsk",
"Beijing"                      => "Asia/Shanghai",
"Chongqing"                    => "Asia/Chongqing",
"Hong Kong"                    => "Asia/Hong_Kong",
"Urumqi"                       => "Asia/Urumqi",
"Kuala Lumpur"                 => "Asia/Kuala_Lumpur",
"Singapore"                    => "Asia/Singapore",
"Taipei"                       => "Asia/Taipei",
"Perth"                        => "Australia/Perth",
"Irkutsk"                      => "Asia/Irkutsk",
"Ulaanbaatar"                  => "Asia/Ulaanbaatar",
"Seoul"                        => "Asia/Seoul",
"Osaka"                        => "Asia/Tokyo",
"Sapporo"                      => "Asia/Tokyo",
"Tokyo"                        => "Asia/Tokyo",
"Yakutsk"                      => "Asia/Yakutsk",
"Darwin"                       => "Australia/Darwin",
"Adelaide"                     => "Australia/Adelaide",
"Canberra"                     => "Australia/Canberra",
"Melbourne"                    => "Australia/Melbourne",
"Sydney"                       => "Australia/Sydney",
"Brisbane"                     => "Australia/Brisbane",
"Hobart"                       => "Australia/Hobart",
"Vladivostok"                  => "Asia/Vladivostok",
"Guam"                         => "Pacific/Guam",
"Port Moresby"                 => "Pacific/Port_Moresby",
"Magadan"                      => "Asia/Magadan",
"Srednekolymsk"                => "Asia/Srednekolymsk",
"Solomon Is."                  => "Pacific/Guadalcanal",
"New Caledonia"                => "Pacific/Noumea",
"Fiji"                         => "Pacific/Fiji",
"Kamchatka"                    => "Asia/Kamchatka",
"Marshall Is."                 => "Pacific/Majuro",
"Auckland"                     => "Pacific/Auckland",
"Wellington"                   => "Pacific/Auckland",
"Nuku'alofa"                   => "Pacific/Tongatapu",
"Tokelau Is."                  => "Pacific/Fakaofo",
"Chatham Is."                  => "Pacific/Chatham",
"Samoa"                        => "Pacific/Apia"
}

Attributes

[R]	`name`
[R]	`tzinfo`

Public class methods

`[](arg)`

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.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 234
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

`all()`

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.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 225
def all
  @zones ||= zones_map.values.sort
end

`country_zones(country_code)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 262
def country_zones(country_code)
  code = country_code.to_s.upcase
  @country_zones[code] ||= load_country_zones(code)
end

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

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).

GitHub

`find_tzinfo(name)`

Source code GitHub

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

`new(name)`

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.)

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 218
def new(name)
  self[name]
end

`seconds_to_utc_offset(seconds, colon = true)`

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"

Source code GitHub

# File activesupport/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()`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 256
def us_zones
  country_zones(:us)
end

Public instance methods

`<=>(zone)`

Compare this time zone to the parameter. The two are compared first on their offsets, and then by name.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 335
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)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 344
def =~(re)
  re === name || re === MAPPING[name]
end

`at(*args)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 381
def at(*args)
  Time.at(*args).utc.in_time_zone(self)
end

`formatted_offset(colon = true, alternate_utc_string = nil)`

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"

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 329
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)`

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.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 398
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

`local(*args)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 365
def local(*args)
  time = Time.utc(*args)
  ActiveSupport::TimeWithZone.new(nil, self, time)
end

`local_to_utc(time, dst = true)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 553
def local_to_utc(time, dst = true)
  tzinfo.local_to_utc(time, dst)
end

`match?(re)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 350
def match?(re)
  (re == name) || (re == MAPPING[name]) ||
    ((Regexp === re) && (re.match?(name) || re.match?(MAPPING[name])))
end

`now()`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 518
def now
  time_now.utc.in_time_zone(self)
end

`parse(str, now = now())`

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.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 455
def parse(str, now = now())
  parts_to_time(Date._parse(str, false), now)
end

`period_for_local(time, dst = true)`

Available so that TimeZone instances respond like TZInfo::Timezone instances.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 565
def period_for_local(time, dst = true)
  tzinfo.period_for_local(time, dst) { |periods| periods.last }
end

`period_for_utc(time)`

Available so that TimeZone instances respond like TZInfo::Timezone instances.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 559
def period_for_utc(time)
  tzinfo.period_for_utc(time)
end

`rfc3339(str)`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 471
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())`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 509
def strptime(str, format, now = now())
  parts_to_time(DateTime._strptime(str, format), now)
end

`to_s()`

Returns a textual representation of this time zone.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 356
def to_s
  "(GMT#{formatted_offset}) #{name}"
end

`today()`

Returns the current date in this time zone.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 523
def today
  tzinfo.now.to_date
end

`tomorrow()`

Returns the next date in this time zone.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 528
def tomorrow
  today + 1
end

`utc_offset()`

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

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 319
def utc_offset
  @utc_offset || tzinfo&.current_period&.base_utc_offset
end

`utc_to_local(time)`

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.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 544
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

`yesterday()`

Returns the previous date in this time zone.

Source code GitHub

# File activesupport/lib/active_support/values/time_zone.rb, line 533
def yesterday
  today - 1
end

Definition files

activesupport/lib/active_support/values/time_zone.rb

class ActiveSupport::TimeZone

Inherits From

Constants

MAPPING

Attributes

Public class methods

[](arg)

all()

country_zones(country_code)

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

find_tzinfo(name)

new(name)

seconds_to_utc_offset(seconds, colon = true)

us_zones()

Public instance methods

<=>(zone)

=~(re)

at(*args)

formatted_offset(colon = true, alternate_utc_string = nil)

iso8601(str)

local(*args)

local_to_utc(time, dst = true)

match?(re)

now()

parse(str, now = now())

period_for_local(time, dst = true)

period_for_utc(time)

rfc3339(str)

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

to_s()

today()

tomorrow()

utc_offset()

utc_to_local(time)

yesterday()

Definition files

class `ActiveSupport::TimeZone`

`MAPPING`

`[](arg)`

`all()`

`country_zones(country_code)`

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

`find_tzinfo(name)`

`new(name)`

`seconds_to_utc_offset(seconds, colon = true)`

`us_zones()`

`<=>(zone)`

`=~(re)`

`at(*args)`

`formatted_offset(colon = true, alternate_utc_string = nil)`

`iso8601(str)`

`local(*args)`

`local_to_utc(time, dst = true)`

`match?(re)`

`now()`

`parse(str, now = now())`

`period_for_local(time, dst = true)`

`period_for_utc(time)`

`rfc3339(str)`

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

`to_s()`

`today()`

`tomorrow()`

`utc_offset()`

`utc_to_local(time)`

`yesterday()`