Re: Time zone changes
On all of the cruises I have taken, the ship has changed time to the local time for the port we were entering. As others have said, this is well publicized in advance, either by the daily newsletter, or by a card or flyer in the cabin.
"Twenty years from now, you will be more disappointed by the things you didn't do than the ones you did. So throw off the bowlines. Sail away from the safe harbor. Catch the tradewinds in your sails. Explore, Dream, Discover."