Bubble automatically collects and outputs times in user’s time-zone. This works amazingly well most of the time. However, when you do more advanced things with it, then it can get quite complicated.
For example, if you want to, say, send that time to a third party you also need to have collected the time zone that it was inputted in so that the thirdy party interprets it correctly. If you want user’s to input a time and select a time zone (perhaps a different one than theirs) then you need to translate that time and store it in the DB since Bubble auto-assumes it’s in the user’s time zone.
Hope this helps point you in the right direction. There are more details on the forum for specific code to implement many of the more advanced time-based requirements.