IIRC, our caravan didn't show until after 6 last year.
By the time we got our ish together, hellos all around, etc, we didn't get food til 8ish (getting lost and passing the restaurant a couple times didn't help).
Setting the time for 9 might be pushing it, but with the difficulty of rounding everyone up, heading out, getting seated and finally getting served, it's probably fair to say we'll still be yuckin it up at Buckets at that time.