4. In theory, you can book Sunday as soon as you scan in on Friday. HOWEVER, we were there opening weekend of ROTR, and we had Saturday and Sunday booked, and then needed to book Monday also (a holiday). After we scanned in Saturday, it would not let me book Monday. The system crashed due to ROTR BGs, and no tickets were recognized nor fast passes could be booked for an hour. The system took a long time to reset, and I was not able to book Monday until about 6am Sunday morning. I checked all day Saturday, Saturday night, and even at 2am Sunday (thinking maybe the system would reset at Midnight), but still not able to book. So most of the time, yes, you can book as soon as you scan in (which is what happened on Monday when we scanned in (Sunday also crashed the ticket system, so we were again locked out from a new reservation but it didn’t matter since we had reserved Monday at that point and that was the final day we needed)).