[KingMob]

"Just use UTC" is another, albeit more subtle, falsehood programmers believe about date/time.

It's fine for distributed logging and computer-only usage, but fails in obscure ways once humans, time zones, travel, laws, and/or daylight saving time get involved.

If you're scheduling events for humans, and can't immediately list the reasons your app is an exception to the above, store the time zone to be safe. You probably don't have big data, and nobody will notice the minuscule overhead.