timezones function | r timezone list
Names"UTC"anditssynonym"GMT"areacceptedonallplatforms.WhereOSesdescribetheirvalidtimezonescanbeobscure.ThehelpfortheCfunctiontzsetcanbehelpful,butitcanalsobeinaccurate.ThereisacumbersomePOSIXspecification(listedunderenvironmentvariableTZathttp://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08[1]),whichisoftenatleastpartiallysupported,butthereareothermoreuser-friendlywaystospecifytimezones.AlmostallRplatformsmakeuseofatime-zonedatabaseoriginallycompiledbyArthurDavidOls...
Names "UTC" and its synonym "GMT" are accepted on all platforms.
Where OSes describe their valid time zones can be obscure. The help for the C function tzset can be helpful, but it can also be inaccurate. There is a cumbersome POSIX specification (listed under environment variable TZ at http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08[1]), which is often at least partially supported, but there are other more user-friendly ways to specify time zones.
Almost all R platforms make use of a time-zone database originally compiled by Arthur David Olson and now managed by IANA, in which the preferred way to refer to a time zone is by a location (typically of a city), e.g., Europe/London, America/Los_Angeles, Pacific/Easter within a ‘time zone region’. Some traditional designations are also allowed such as EST5EDT or GB. (Beware that some of these designations may not be what you expect: in particular EST is a time z...