allowing users to adjust time zone of timestamp is super helpful.
And, also, it is super annoying to see photos taken earlier listed behind those taken later when sorted by taken time if traveling westward across time zones, or eastward across IDL. And to sync photos time order amongst photos taken by friends, who may set camera time zone differently (or auto time zone setting not/available on their cameras) in the same trip.
Metadata of "XMP" supports time zone, and UTC time in "EXIF: GPS block" may derive time zone from, and EXIF since version 2.31 in 2016 also supports time zone.
. To consider time zone while "sorting by date/time", if time zone info is available or can be derived (in file properties, or photo metadata: XMP, EXIF GPS block, EXIF 2.31 or later, etc).
. Suggesting to add "time zone setting" in "Change Timestamp" "Use" block with "specific date and time" and "from other time property, with offset".
If time zone info not available, adding it into photo metadata or file properties; if available, allowing to edit it. We can select "unchanged", "none" (clear if existed), and a specific new time zone offset.
See attached demo image for concepts.
Here also attaches crops of some snapshots of another application named "GeoSetter" in action. We noticed that not all the timestamps time zone were changed properly in this demo. (home PC and camera setting as TZ+8 and travel to TZ-7, where photo time zone +8 changed to time zone -7 in the demo, an "XMP" metadata, which was not existed, is inserted to the original photo file in this demo). I'd guess that the behavior of "16:00 TZ+8" changed to "16:00 TZ-7", with timestamp adjust offset 0, is not very appropriate. It is better to change to "01:00 TZ-7" as the same UTC time but in different time zones for the purpose.
Before
After
