I don't think you should look at it that way(this is on a low fat diet of course..). Cheat days are needed not just because you can't handle the diet it self and that you are to tempted to eat junk food, but also to bump up your metabolism after a 1 or 2 week strict cuttingdiet.
Let's say you eat 1000cals below your maintenance calorie intake(of course I mean that you slowly should lower calories, but let's say U have reached -1000cals from what U have to eat to maintain your bodyweight). After a week or so U do not by far burn as many calories as u did a week ago. One cheat won't make U fat, I think It will help U a lot.
I always have cheating days when I cut with a low fat intake. I have it on saturdays and I eat what I want. On the sunday I have gained about 4lb, on monday I'm still at +2lb from saturday morning. The next saturday morning I'm down 1lb-1.5lb from the week before.