The best time to book a flight for a cheap holiday is 54 days (7.5 weeks) in advance, new research has revealed.
According to CheapAir.com, fares start to drop around 225 days (7.5 months) before a flight date and they continue to drop slowly but steadily until they reach their lowest price 54 days before departure.
The American travel booking website's study showed that the worst day to book is the day before flying, followed by two days before and up to 13 days in advance.
While the time you book also depends on the destination you're flying to, the prime booking window was revealed as between 29 and 104 days before a flight.
CheapAir.com analysed over four million flights in 2013 while researching how customers could bag the best bargain flights.
Meanwhile, UK-based Skyscanner recently revealed the best time to book a cheap flight is five weeks in advance.
The travel search website analysed millions of flights and launched a Best Time To Book tool to help travellers get the best price. For budget flights, Skyscanner advises booking five weeks before flying, while scheduled flights should be booked six weeks in advance.
Finding the best time to go is also possible with the month-by-month view of flight prices. The tool shows that January is the cheapest month to travel, when holidaymakers can save up to 13 per cent on flights travelling in the third week of the month.
The destination guide also tells you exactly when you should book when travelling to popular holiday spots. For a trip to Turkey, for example, you should book 13 weeks in advance, while breaks to the US should be booked 21 weeks before travelling to get the best deal.