Where does that leave between -10? Is that time to clear out the day guests? I just looked on the official site (WDW), and it doesn't list hours at the moment.
Yes, the time between 9 and 10 allows day guests who got in line for Remy, Frozen, GotG, etc. at 8:55 PM to ride and leave, not to mention the hordes who watch the fireworks show from 9:00 to 9:20 or so and then need to depart.