Akeman has a 10 minute bid window at then end of each Casino Chip Gallery auction, at least according to the rules posted on his website. It reads (in relevant part):

BIDDING ON CHIPS
Bids can be placed by telephone
(702) 382-0825
(888) 593-7830
(888) 593-7840
Bids will be taken between Now and Sunday 04/01/2001 during normal business hours 8 A.M. to 5 P.M. PST. To prevent anyone from getting shut out of the bidding, we will take bids until the first 10 minutes of dead bidding after 3:00 pm (PST) on the last day of Bid Board.