Calorie cycling has some really solid studies behind it. But as another poster said, "free" can't mean you eat an entire chocolate cake. for a 1200-1500 cal diet, you probably never want to go above 1800. so maybe 300-400 cals more.
BUT, the real key is what is happening at the end of your week. if your calories avergage at 1500 x 7, (so 10,500? - i'm bad at math), then you are ok either way. I remember when people who knew they were having an anniversay or going to a special dinner would eat at the low end of their range every day, so they had an extra 500 or so cals to play with that day.