We did the day room back in May when we had a 5:00 flight. Most airlines will not allow you to check-in more than 4 hours before the flight. We arrived at the airport at 8:30 am, but couldn't check our luggage until 1:00. The Hyatt let us leave our suitcases in the lobby until we could check in with the airline which was great. We went swimming for a while, then checked in and got rid of our luggage and got our boarding passes. The airlines usually start boarding about 45 minutes before departure time, so you should allow about an hour to check-out of the Hyatt, get through security and get to the gate. We were travelling home on Memorial Day weekend, so the security lines were very crowded due to the holiday weekend, but we got to the gate in plenty of time. If you have your boarding pass, the airline knows you're there, so give yourself about 45 minutes to an hour. The Hyatt is inside the airport and there are plenty of places inside the airport where you can meet your in-laws for lunch. We ate at Chili's, but there's a restaurant inside the Hyatt that I heard is very good. Have fun.