On 10/21/20 10:12 AM, Neil Fuller via tz wrote:
The Stock Android settings UI, starting with Android Pie (9.0), allows users to select from the fixed "Etc/GMT-5" style identifiers from TZDB
How does that work at the user level? I have an Android 10 phone (build QQ1A.200105.032), and couldn't see these UI options under either "Settings>System>Date & time>Time zone" or "Clock>⋮>Settings>Home time zone" (these have different UIs).
The current Etc/GMT[+-] zone identifiers in TZDB only cover whole hour offsets. There are various places that use 30 minute offsets, and a few that use 45/15 minute offsets [2].
I suppose we could add IDs for non-hour offsets currently in use. I worry, though, that there will be more odd offsets outside the civil-aviation application area, such as the offsets that various astronomical observatories use (as Steve Allen mentioned). In GNU/Linux the way to solve this problem is to use a TZ setting like TZ='<+0545>-5:45' for Nepal (or TZ='NPT-5:45' for older POSIX). Does this work for Android? If so, I suggest going that way. If not, perhaps POSIX TZ support should be added to Android; that shouldn't be hard, and would improve functionality and compatibility in other areas too. If it couldn't be done for Android it could at least be done for the Clock app.