zgo.at/tz

Package tz provides a wrapper for time.Location with additional information about timezones.

Every timezone is represented by a zone name (Europe/Amsterdam) and a country (NL). The rationale for this is mostly a user interface one: it makes more sense to display a list of countries first and then a list of timezones, instead of just presenting a huge list of timezones.

For example, my current TZ is Asia/Makkasar (WITA), but it's much easier to select "Indonesia" from a list, and then choose one of the four timezones in Indonesia:

Indonesia: Asia/Jayapura  (WIT)  – New Guinea (West Papua / Irian Jaya); Malukus/Moluccas
Indonesia: Asia/Makassar  (WITA) – Borneo (east, south); Sulawesi/Celebes, Bali, Nusa Tengarra; Timor (west)
Indonesia: Asia/Pontianak (WIB)  – Borneo (west, central)
Indonesia: Asia/Jakarta   (WIB)  – Java, Sumatra

We need to store both to make sure people who fill in "Isle of Man, Europe/London" aren't shown "you selected Britain, Europe/London" when they revisit a settings page.