[tz] Support for Etc/GMT -style zones ids with partial hours
eggert at cs.ucla.edu
Wed Oct 21 17:50:24 UTC 2020
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 .
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.
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