Yeah probably squats. But you could also do it after the workout that trains the muscle group or lift you want to bring up the most. Based off that schedule I would do the carb nite after the press day on friday. Not because it was the most demanding, but because itll give you more glycogen reserves come mondays squat session and the squat/leg workout will help you deplete glycogen and get back into fat burning. But I dont think its going to make a huge difference, thats just what Id do.