#nostr notes have a created_at “unix timestamp”. I assume that’s in UTC?

Is there a way for a client to add a user’s time zone offset? That would allow clients to optionally display times in that user’s local time zone.

Sometimes that context matters. 

Ex: If someone posts about their morning/evening, it’s useful to know what time they were talking about it.   “Can’t wait till lunch break.”  Is it 11am or 7am there?