I think the main thing to remember is that dates and times have very different semantics when used for different purposes. If you are referring to an instant i

I think the main thing to remember is that dates and times have very different semantics when used for different purposes. If you are referring to an instant in time, then just using UTC is reasonable. If you are referring to a past event and both the local time and precise instant are relevant, then the local time with a timezone offset is reasonable. If you are scheduling events on a calendar, however, like "8 AM every monday for the next four weeks", then yes, you need to store the abstract time zone name so that the calendar program can translate each instance of that schedule to the appropriate instant.