Book 53 days in advance and travel on a Tuesday night

This is the advice from price comparison site Momondo, who have compiled statistics on the best time to book a flight. According to the company, the cheapest flights were booked an average of 53 days before departure, and offered savings of up to 29 percent. 70 percent of flights are cheapest on Tuesdays, and roughly every other trip is cheaper at night. The most expensive time to travel is in the afternoon. What you should not do is book on the day of departure as this is when flights are dearest. Saturdays should also be avoided as they are usually expensive, closely followed by Fridays.