I light my smoker and then rub the ribs while the cooker heats up. So probably an hour or so. I like to make sure it's long enough that the rub has a time to melt onto the meat.
Early on I rubbed the night before and they came out hammy. That was the last time. Although after reading this thread it has me wondering if my hammy ribs might have been Tyson from Walmart also. Pork butt being a bigger cut, I have gotten away with going overnight, although I don't feel that is necessary either.
"I can get a good look at a T-bone by sticking my head up a bull's a$$, but I'd rather take a butcher's word for it". - Tommy Callahan III
XL Big Green Egg, 22.5 Weber OTS, WSJ Gold/Mini WSM, 18" & 22" WSM, UDS "No.8"
Flyers Orange Thermapen
Napkin Killers BBQ