If I recall correctly, they could go until 5:00 pm, as the intimates at all locations (except for WP) can only be booked on an "odd" hour...ie 11:00 , 1:00 , 3:00 , 5:00 p.m.
On the other hand, intimates at the WP are only scheduled on even hours
10:00, 12:00, 2:00, up until 6:00 p.m and intimate weddings can only be held Monday - Thursday at WP (as of October 2005).
I booked ours at 3:00 p.m. and it worked perfectly because we booked group reservations for 5:20 p.m. dining.
By the time we started the wedding, had the cake/champagne reception and then finished all of our pics...we ended up arriving at the restaurant at 5:00 p.m. ....perfect timing.
Our wedding day events ended about 7:30 p.m, which is the time we had scheduled for our towncars to pick us all up.