Sea Break

I noticed the time in port on the 7 day Eastern Caribbean route (HMC, GT, San Juan, St. Thomas) has all been reduced by an hour. Any idea, besides financial, as to why? Did this one last year and looking to do it again. Last year, for example, departure out of San Juan was 11PM and now 10PM. HMC was 3PM, now 2PM. St. Thomas was 5PM, now 4PM, etc. Seems odd, as this itinerary has always been the same until now.