tz database

The tz database is a collaborative compilation of information about the world's time zones, primarily intended for use with computer programs and operating systems.[2] Paul Eggert is its current editor and maintainer,[3] with the organizational backing of ICANN.[4] The tz database is also known as tzdata, the zoneinfo database or IANA time zone database, and occasionally as the Olson database, referring to the founding contributor, Arthur David Olson.[5]

The tz database partitions the world into regions where local clocks have, since 1970, all been the same. This map, made by combining the 2017a edition of the database with OpenStreetMap data, is of all the regions outside Antarctica.[1]

Its uniform naming convention for time zones, such as America/New_York and Europe/Paris, was designed by Paul Eggert.[6] The database attempts to record historical time zones and all civil changes since 1970, the Unix time epoch.[7] It also includes transitions such as daylight saving time, and also records leap seconds.[8]

The database, as well as some reference source code, is in the public domain.[9] New editions of the database and code are published as changes warrant, usually several times per year.[10]