I never take advanced bookings for that very reason, but as you do and he has let you down a few times before then I think I would tell other potential clients that want to book to call on the day to see if you are available, at least that way you may still cover the time he booked and not lose out. As it is only Tuesday there is no reason why you may not still cover the time booked.
For me, regular clients get guaranteed bookings, but if they start messing me about and not showing, then they slide down the rankings, I still take the booking but they may find they have been double booked.
Sarah x x x