I Was told by a Carnival rep., that the ship always stays on the time zone they were in at the Port they left from. So if you are leaving from Tampa Fl, you will stay on Eastern. Standard Time. Depending when you sail, will determine if you are on daylight savings time. We are sailing on the Inspiration on 5/30 , and that will be daylingt savings time.
It isn't true that the ship will always stay on the homeport time. We were on the Conquest and they changed from Central to Eastern in Jamaca and then back to Central when we were in Cozumel. They didn't announce they were switching back had to read it in the Capers. So read the Capers and ask one of the social directors on the ship.