generally Marriott now goes with 48 hours in advance to cancel with no charge. remember it was 24 hours at least for members not too long ago. I booked a room at Newton Marriott and had too cancel .I did it a little more than 48 before check in . well when I looked at my credit card I noticed a had been charged a one day charge. I called them and they said since the Starwood merger they were now going with 72 hours in advance. Given I am a LPP they reverse and waived the charge. I just posted this for people to look carefully at each hotel's policy. I of course didn't because I went with the assumption of the standard 48 hours.