As another poster already said, UTC is the correct choice for any kind of timestamps and for the storage of any time information about the past. (Actually TAI is an even better choice for these purposes.)

For future events, the "time" when they will occur is not "time", but a different data type, which should be called "legal time", "local time" or the like.

The "local time" for future events must include the geographic location attached to the event, from which the applicable time zone can be derived, at a time close to when the event is due.