I don't really have naughty days as such. I do eat more synful foods at the weekend, and I drink wine too! I find that uses up most of my syn allowance and I feel like I am being naughty. I don't always add up my weekend syns, but I am learning to control myself a bit more, so I go bonkers in a more controlled style and not panic so much...so I stay within 105 syns a week.
Some people eat whatever they want on WI day, after WI...that's their naughty time. I don't do that...I save myself for weekend still!