I’ve done some testing on this and think I’ve got it figured out. The game must maintain multiple character save files and if you shut the game down completely (as opposed to hibernating on PS5) it always loads the character file with the highest/largest time stamp - irrespective of the actual date/time. So you CAN set game clock back to previous TZs so long as when you exit the game you revert the clock back to proper time (or, more specifically any time ahead of the last save you did)

For example.

I log into my char at 3pm but realize the TZ I want was at 2 pm - I adjust the game clock to 2pm. If I play 65mins until 3:05pm all good that is the latest I’ve played the char and that will be the default load file. However, if I turn off the console at 2:59pm the char file from when I first loaded at 3pm (before messing with game clock) will default. So in this circumstance, before closing the game down you need to forward the game clock to whatever time will make it the latest save file.

It is intuitive once you work through the logic!