Quote Originally Posted by WDWdriver View Post
It's per day, but it's a lot more complicated than that. Let's say an attraction's OHRC (operational hourly ride capacity) is 2000 (a more realistic number), and the park will be open for 10 hours as you said.
It actually isn't really terribly complicated- one of the factors that actually controls the fastpass distribution rate is the current standby wait time.

For example, if our hourly ride capacity we estimate is 2000 guests per hour, we take 80 percent of that (or whatever capacity we've reserved for fastpass) so 1600 and then divide that by the current standby wait time (in minutes)

So if the wait is one hour, that gives us roughly 26.6 guests per minute using our example of 2000 guests per hour total capacity. So when we've handed out 26.6 fastpass tickets, bump the return window 1 minute (to slightly simplify things the smallest window used generally is 5 minutes so after we've distributed 133 fastpasses the return window moves 5 minutes).

If there is a long wait for the attraction, say 90 minutes then using the same formula we reduce the number of fastpasses that are handed out before we bump up the return window. Likewise if the standby wait is short, that means we have unused capacity so hand out more fastpasses before we bump up the return window.