I do the checking with MS the first day I can reserve too. I find they are very good at advising if it should be made day by day or not. When I called for the GV in October, they suggested I needed to do that, but when I called for the 2 bedroom early December, they said there was no need to, so I made the first part of the ressie, and then called again at the check out end date to make the rest of it. They flag it in their computer, so when you call the first day, they plug in the end date too. Then when you call back, they know how much you have left.