My trip is a little over the 45 day mark... I think people start cancelling before 45 days (packages have to be paid in full by then). Just keep looking.
When I first clicked on it it still showed my original time slot, and I almost didn't realize that it opened up other times - if no other times are available it will say so, if you click on it and you don't get that message, be sure to click on the drop down arrow to see all times available.