when I when I work for Marriott, the standard was 12 pm. That did very a little from hotel to hotel, so you should always ask at check-in. Also, if you do want a later checkout you should ask for that at check in as well.Marriott Rewards members do get late check-out depending on what tier they are, but you still have to ask at check-in in order for the desk to know that you are going to use you're late check-out privileges. Play check out times can go as late as 4 p.m. for platinum members, however please do not request that late of a check out unless you are going to be using the room for that long. If you request a 4 p.m. check out, you are basically making the housekeeper cleaning your room stay until 5 or 5:30 in order to get the room flipped for the day. Or, you are forcing the hotel to put your room out of order for the night because all the housekeepers have already gone home.