The deadline is March 23 to insure getting the meeting rate or space in the hotel.
Full info is attached.
Attached is a registration form for hotel reservations. This special rate will apply from Friday, May 5 through Saturday, May 13 only. May is a very popular meeting month in Seattle, and the hotel will fill up quickly. If you want to be guaranteed a room, please make your reservation by the above date . The conference rate will still be honored after this date, but on a space availability basis only .