I find same day booking work best for me, not because of anything, but things that are booked days in advance mean that I have had to reserve time. More often than not those scheduled times are subject to change or there's an urgent need to reschedule, or there's a delay minutes before im supposed to meet them at the incall. I find advanced booking leads to more flakiness, if I message a girl at 2 Pm and ask if she's available for a 4:00, she'll say yes because she is. Where a girl im booking with on Saturday for a Wednesday session will have an excuse to change the time, ask to reschedule or have a reason to be late. At least that has been my experience.