I would like to be able to use Photo Mechanic to designate the time zone in which a given image was created (i.e. GMT +1, -5, -8, etc.) for non-geo-tagged images. That's assuming such information can be saved in the metadata embedded in an image.
What I'm finding is non-geo-tagged images edited at home after a job/trip in another time zone, then uploaded to a cloud service, such as Google Photos, appear out of sync with geo-tagged images from the same time because they show the incorrect time zone (they show the time zone at time of upload rather than at time of capture).
A solution is to reverse geo-tag such images in PM before uploading them. But this has the potential to be time consuming if I wish to do it accurately (as opposed to picking a random location in that time zone). There may also be times when it's undesirable to location tag images, but still want them to be in the correct time zone.
Being able to set the time zone could be a quick batch fix without having to set 'fake' GPS coordinates, assuming such a tag would be recognized by other software...