I own two weeks at Sheraton Desert Oasis that were bought resale and are not in the Starwood Vacation Network. I vaguely remember that in the past I could change a reservation up until a day before check in at no cost and without any restrictions on the new week that I could reserve. I was talking to a Starwood rep today and she said there was no charge to change my reservation but that since my existing reservation is within 60 days of check in, if I cancel or change it I cannot book a different date unless the new date was within 60 days of check in. I think this is the case if you're in the SVN but if you're not, my understanding is that there is no restriction on how far in advance you can reserve a new week. Are there any Starwood experts on here who can clarify this? Thanks.