When they say "60 days", it's not always clear exactly when your window opens. For instance, if the date you are scheduling for is 7/8, the day your window opens is 5/9. The times are unsure, from what I could gather. I tried to make a reservation at 12:00 a.m. PST and it didn't work. It did work at 3:00 a.m. PST. It could have worked sometime in between these times but it's hard to tell. These are just my observations based on very limited experience.