Every time I try to make a reservation, every available slot is full. This makes me think the slots fill up within potentially as little as half an hour or less after they first become available.
In light of this it seems like the best way to successfully schedule something would be to check right after slots become available. Unfortunately, I do not know when this is.
Do slots become available at a consistent time or is it all over the place? It doesn't seem to me like it's consistent. I've seen new slots (eg. thirty days out) appear as being full at 12:15am CST and sometimes they're not even listing slots, full or otherwise, even at 10am, but then when I check at 10pm they're full. Maybe there's a pattern but if so I'm having a tough time gleaning it. Due to their use of a captcha I can't really write a script to check either.