Your return time will be further and further away as the day moves on. So, for example, if you get your first FP at 9.30 it could be for 10am or 10.10, then get your next one at 10.10 it could be for 10.50 and so on. In peak season, if you get an FP at 2pm it could be for as far away as 6pm. So the more you utilise FPs in the a.m. the better! If the standby line is less than 10 mins don't waste your FP opportunity there, get an FP for something busier/slower.