In your case, unfortunately, the timing doesn't work: the tours ideed start at a fixed time - 9am and 12pm and end at 3pm and 6pm.
When we did our layover we had to do a quick Mattress run at the Courtyard close to the airport. So we asked which tour we can get on, and he said there is one at 9am, and I said we might not be able to do it and then he said to me to get back at 10am.
I don't know exactly what he meant since we decided to take the 9am tour because you can't get 3 kids calm in a hotel room during daytime.