The best time to book a flight ticket is eight weeks before departure, according to new research by an economist.

Best Time to Book A Flight

Makoto Watanabe has created a formula which calculates the optimum time to book. It evaluates the risks of booking too close to the departure date, when the flights can be fully booked or prices high, and the risks of booking too early, when the travellers’ plans can change.

The yet-to-be-published findings suggest airline tickets are also cheaper when bought in the afternoon. He speculates that airlines assume business travellers are more likely to book in the morning and leisure travellers in the afternoon or evening.

The Japanese economist’s new work stems from a paper he published last year in the Economic Journal entitled Advance Purchase Discounts versus Clearance Sales, which analysed the pricing of tickets.

In it Watanabe and his co-author, Marc Möller, write: “When we book our flights to the UK weeks ahead we have to account for the possibility of unforeseen events which make our trip to London impossible. In order to make consumers take their chances, airlines have to offer advance purchase discounts. As a consequence, ticket prices increase as the travel date approaches.”

The pair contrast this with the purchase of theatre tickets, which they say tend to be subject to a clearance sale close to the performance date. “Air travel to London is offered by relatively few carriers, while West End musicals are unlikely to sell out,” they write.

According to this research the best time to book an airline ticket is eight weeks before your departure date.