Always the day before. A few years ago, we were sailing from San Juan, and as I love Ft. Lauderdale, we decided to fly there the day before and rent a car to see the town. We were booked on an American Airlines flight to San Juan the next afternoon which was fine as the sailing was not until 10:00 p.m. but due to constant delays, we came within minutes of missing the ship, so I would never arrive at the port of embarkation on sailing day again. Will always give myself plenty of wiggle room......