I'm not very sure either, but I thought award availability is more real-time or done on a continuous basis. the reason people call at midnight was more because of the 330-day (or whatever number of days) - i.e. awards are available only 330 days in advance starting at midnight of that day ?

but if you're not looking at this 330-day rule and not really trying to get award the first day it's theoretically released, I think award availability actually could change continuously just like any other inventory bucket...I think I certainly have my award waitlist cleared in different cases in different times of the day...