What woud you figure for seating time for a Mother's day brunch?

We open at 10am, filling the dining room, how long should we figure the guests are going to stay???

Thanks,
Chad

It's been my experience that the average table turn is right around 1 hour for ala carte and slighlt longer for buffet. Also we overbook resos to make up for the average 10 percent that noshow/ no call.