Booking a trip early is a no-brainer—not only will it save you money, but it’ll give you more travel and lodging options. But the real secret in booking in advance is to book your flights on a Tuesday, Wednesday, or Saturday. Airlines often offer site-wide sales in the middle of the week to entice flyers and lower costs on weekends for leisure travelers who tend to browse on weekends. This means that the same seat on the same flight could be substantially less if purchased on one of these days. While this trick isn’t guaranteed, it’s one of the easiest ways to save money on a flight.