Last modified: 2014-08-22 12:49:04 UTC
With bug 505 fixed, users will now be able to specify a zoneinfo timezone name (such as "America/Los_Angeles") in place of a manually-calculated offset ("-08:00"). This is good, but the list of places is long -- 445 entries currently come up in the list available on my test installation. Even if localization of names is added, the list isn't super easy to pick from. For a long time we've had a button to fill in the offset from the client computer's settings via JavaScript, but this only gives us the current offset; we need a zone location to handle DST transitions. It would, however, be possible to show a restricted list which matches the client settings. For instance a match for -08:00 in December would require only picking from: +---------------------+ | America/Dawson | | America/Ensenada | | America/Los_Angeles | | America/Tijuana | | America/Vancouver | | America/Whitehorse | | Pacific/Pitcairn | +---------------------+ At the moment (December 2008), the biggest list would be for UTC+1, which comes up with 46 locations in Africa and Europe. Here's a breakdown, with some locations just for fun: +---------+----------+ | minutes | count(*) | +---------+----------+ | -660 | 5 | | -600 | 7 | <- Hawaii | -570 | 1 | | -540 | 5 | | -480 | 7 | <- US west coast | -420 | 12 | | -360 | 23 | | -300 | 36 | <- US east coast | -270 | 1 | | -240 | 33 | | -210 | 1 | | -180 | 18 | | -120 | 21 | | -60 | 3 | | 0 | 30 | <- UK | 60 | 46 | <- Europe | 120 | 40 | | 180 | 21 | <- Moscow | 210 | 1 | | 240 | 9 | | 270 | 1 | | 300 | 12 | | 330 | 3 | | 345 | 1 | | 360 | 12 | | 390 | 2 | | 420 | 11 | <- Australia west coast (DST) | 480 | 21 | <- China | 540 | 10 | <- Japan, Korea, Australia east coast (DST) | 570 | 2 | | 585 | 1 | | 600 | 10 | | 630 | 4 | | 660 | 17 | | 690 | 1 | | 720 | 10 | <- New Zealand (DST) | 780 | 5 | | 825 | 1 | | 840 | 1 | +---------+----------+
I'm using this sort of pruning with a visual display in [[mw:Extension:TimeZonePicker]], still experimental.
Still valid in 2014; "Time zone" field on https://en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-rendering under mw-prefsection-rendering-timeoffset offers only: * "Fill in from browser" (guesstimezone) * "Other (specify offset)" (timezoneuseoffset) but not taking the timezone from the browser and then choosing the exact timezone (and DST settings of a country) based on a list of locations limited to locations in that timezone.