You may be aware of some spirited discussion on the iana.org/time-zones mailing list regarding a recent change to merge similar timezones (i.e. with common rules post-1970).

This change has seen a lot of resistance and calls to revert the decision, however if it does remain in place the following changes you can expect more aliases/redirects in upcoming releases of the timezone definitions (and subsequently on sites such as tzurl.org):

The following list is indicative of how many timezones may be merged:

  • africa (Africa/Abidjan, Ghana, Africa/Accra, Indian/Reunion) (Indian/Mahe)
  • antarctica (Indian/Kerguelen, Antarctica/DumontDUrville) (Antarctica/Syowa, Antarctica/Vostok)
  • asia (Asia/Brunei, Asia/Urumqi, NBorneo, Asia/Kuala_Lumpur) (Asia/Kuching, Indian/Maldives, Asia/Riyadh, Asia/Bangkok) (Asia/Dubai)
  • australasia (Indian/Christmas, Indian/Cocos, Pacific/Gambier) (Pacific/Tahiti, Pacific/Tarawa, Pacific/Majuro, Pacific/Chuuk) (Pacific/Pohnpei, Pacific/Palau, Pacific/Port_Moresby) (Pacific/Guadalcanal, Pacific/Funafuti, Pacific/Wake) (Pacific/Wallis)
  • europe (Denmark, Europe/Copenhagen, Iceland, Atlantic/Reykjavik) (Lux, Europe/Luxembourg, Europe/Monaco, Neth, Europe/Amsterdam) (Norway, Europe/Oslo, Europe/Stockholm)
  • northamerica (America/Blanc-Sablon, America/Atikokan) (America/Creston, Bahamas, America/Nassau)
  • southamerica (America/La_Paz, America/Curacao, America/Cayenne) (Atlantic/South_Georgia, America/Port_of_Spain)

The iana.org/time-zones mailing list included extensive discussion on the pros and cons of the change, but I think it is worth considering that timezone rules are defined somewhat arbitrarily by governments of states and regions, and as a result we cannot predict what the future will hold.

A simplification today might lead to more complexity in the future, but we’ll have to see how it plays out on the mailing list.