But here's a fun tip: If the restaraunt's crowded, THAT'S the best time to eat there. You'll get fresher food that way. An empty restaraunt often means the food's been sitting in a heater, possibly long after it's due to replaced with fresh stuff.
Back when I used to work swing shift I would eat fast food every night. Got there around midnight and they made everything fresh. That's one of the biggest reasons I'm a fat ass.