It varies according to how many cruise guests are staying at your hotel, and how many stops your bus needs to make. The night before your cruise you'll get a note delivered to your room telling you what time to have your luggage ready for bell services to pick up, and what time to meet the cruise agent in the lobby.
When we cruised 15 mos ago the luggage was picked up around 8:30 a.m. and we were picked up around 11:30. This was at the Grand Floridian and the bus stopped at two other hotels.