yes, the 7 day can be challenging. We were on the Oct 26 cruise last year so we boarded during Eastern Daylight Savings Time which changed that night to Eastern Standard Time (got that extra hour on the trip), then we went backwards for Grand Cayman and Cozumel and forward again returning to Castawy Cay. The navigators were very helpful in figuring out what time it was
However, you are on vacation and except for missing dinner, a show or an excursion, you really don't care what time it is....