Crock-Pot Timing

I'm making a turkey breast for dinner.  Looking at the recipes for roasting it in my crock pot, I always seem to be right between the "high" and the "low" cook times.  For example, they'll say "Cook on low for 10-12 hours or high for 6-8 hours."

My dilemma is two-fold:  I love the flavor boost from slow cooking, but I never seem to be able to get up at 5:00 am to put it on.  I'm sure you'll have some suggestions, and sure, Thanksgiving or Christmas make it easier, but just an average Friday doesn't get the 5:00 am treatment.

My second dilemma is that I usually can get my bum up to cook early enough that some slow cooking could be enjoyed.  So, here's my formula for when you want slow cooking, but don't want to eat dinner at 10:30 at night.

I'm a mathematician by degree (and I'm not the only one in the trailer park) so bear with me as I give you the math by brute force and then go back and explain it.

Food safety warning:  I don't know all the science for this, so while I don't use the "cook on high" time in my math, I DO NOT use this formula if the recipe doesn't say that the item can be cooked on high.  Also, if I have less time than what the recipe says to cook on high, then I need to wait until a day when I have more time, or, of course, cook it in the oven.

Let T1 = the time the recipe gives if you only cook on low
      T2 = the amount of time I have

First, subtract the time I have from the high time: T3 =  T1 - T2
Then, subtract this time (T3) from the high time (T2):   T4 = T2 - T3

T3 will be the number of hours on high.
T4 is the number of hours on low.

EXAMPLES:
Recipe says:  "Cook 10 hours on low."  I have 8 hours:
T1 = 10
T2 = 8
T3 = 10 - 8 = 2
T4 = 8 - 2 = 6
So, I have eight hours, so I'm going to cook 2 hours on high and 6 hours on low.

Recipe says:  "Cook 12 hours on low."  I have 7 hours.
T1 = 12
T2 = 7
T3 = 12 - 7 = 5
T4 = 7 - 5 = 2
So, I have 7 hours, I would cook 5 hours on high and 2 hours on low.

I'll let you know later how my turkey breast comes out... but right now, my kitchen is already filled with smells of butter, turkey, rosemary and thyme!