Ziptz

Get time zone, daylight saving time, and base offset for any US ZIP code.

ZIP codes are up to date as of May 2024.

Compatibility

Ziptz is tested to work with the following versions of Ruby:

Ruby 3.1.x, 3.2.x, 3.3.x

Installation

Add the gem to your Gemfile:

gem 'ziptz'

Usage

Get the time zone name for any ZIP code:

z = Ziptz.new
z.time_zone_name('97213') #=> "America/Los_Angeles"

Get the time zone offset for any ZIP code:

z.time_zone_offset('97213') #=> -28800

Note that offsets do not include daylight saving time.

Determine if the ZIP code uses Daylight Saving Time:

z.time_zone_uses_dst?('97213') #=> true

Get all the zip codes in a time zone:

z.zips('Pacific/Chuuk') #=> ["96942", "96943"]

Supported Time Zones

America/Adak
America/Anchorage
America/Boise
America/Chicago
America/Denver
America/Detroit
America/Indiana/Indianapolis
America/Indiana/Knox
America/Indiana/Marengo
America/Indiana/Petersburg
America/Indiana/Tell_City
America/Indiana/Vevay
America/Indiana/Vincennes
America/Indiana/Winamac
America/Juneau
America/Kentucky/Louisville
America/Kentucky/Monticello
America/Los_Angeles
America/Menominee
America/Metlakatla
America/New_York
America/Nome
America/North_Dakota/Beulah
America/North_Dakota/Center
America/North_Dakota/New_Salem
America/Phoenix
America/Puerto_Rico
America/Sitka
America/St_Thomas
America/Yakutat
Pacific/Chuuk
Pacific/Guam
Pacific/Honolulu
Pacific/Kosrae
Pacific/Kwajalein
Pacific/Majuro
Pacific/Pago_Pago
Pacific/Palau
Pacific/Pohnpei
Pacific/Saipan
Pacific/Wake

Note that APO/FPO zip codes will not return a known time zone offset.

Prefer raw data?

If you would prefer raw data instead of a gem, see my ZIP Code Time Zones product on AWS Data Exchange to subscribe.

Version 3 breaking changes

APO, DPO, and FPO zip codes are no longer included, because they are non-geographic.
Time zone offsets are now specified in seconds instead of hours.
Time zone are now more granular. The full list of time zones is:
- America/Adak
- America/Anchorage
- America/Boise
- America/Chicago
- America/Denver
- America/Detroit
- America/Indiana/Indianapolis
- America/Indiana/Knox
- America/Indiana/Marengo
- America/Indiana/Petersburg
- America/Indiana/Tell_City
- America/Indiana/Vevay
- America/Indiana/Vincennes
- America/Indiana/Winamac
- America/Juneau
- America/Kentucky/Louisville
- America/Kentucky/Monticello
- America/Los_Angeles
- America/Menominee
- America/Metlakatla
- America/New_York
- America/Nome
- America/North_Dakota/Beulah
- America/North_Dakota/Center
- America/North_Dakota/New_Salem
- America/Phoenix
- America/Puerto_Rico
- America/Sitka
- America/St_Thomas
- America/Yakutat
- Pacific/Chuuk
- Pacific/Guam
- Pacific/Honolulu
- Pacific/Kosrae
- Pacific/Kwajalein
- Pacific/Majuro
- Pacific/Pago_Pago
- Pacific/Palau
- Pacific/Pohnpei
- Pacific/Saipan
- Pacific/Wake

Version 2 breaking changes

Time zone names now reflect standard tz-database names.

V1 Name	V2 Name
Atlantic	America/Puerto_Rico
Eastern	America/New_York
Central	America/Chicago
Mountain	America/Denver
Pacific	America/Los_Angeles
Hawaii-Aleutian Islands	Pacific/Honolulu or America/Adak
American Samoa	Pacific/Pago_Pago
Marshall Islands	Pacific/Majuro
Guam	Pacific/Guam
Palau	Pacific/Palau
Micronesia	Pacific/Pohnpei

License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.