Choosing the wrong day to book a flight can add 66% to the cost of a ticket. There's just one problem - the day changes.
Figures from travel comparison company KAYAK.com shows you'd save £100 on a flight to America if you booked it on Wednesday two weeks before you travel. But if you're flying to Asia to get the best deal you need to book seven months ahead and fly on a Tuesday.
The only rule that applied to all destinations was that it's never cheapest to fly on a Friday or Saturday.
“Business travellers usually travel during the week and try to return on Friday, while leisure travellers usually try to fly on Saturday or Sunday, to use as little annual leave as possible,” said Loella Pehrsson, managing director of KAYAK UK.
“For long-distance routes, travellers should be flexible and avoid the usual travel cycle.”

Find the perfect combination

You can save a lot of money by booking on the cheapest dates. To do that, you need to time two things - when you book, and what day you will actually fly on. 

When to book


Save hundreds booking on the right day
Save hundreds booking on the right day 


For most destinations, booking far in advance is the answer. But not all.
If you're flying to Europe, a month ahead is the right time to book – saving you up to 66% on the cost of a ticket. For the US and Canada, two weeks ahead is the ideal time, with flights then on average £100 cheaper.
On the flip side, you get the best deal on flights to Asia by booking seven months ahead. And flights to South America and the Middle East are cheapest five months before they take off.
The full list:

Source: KAYAK 


What day to fly

The cheapest day to fly on also depends on where you are going.
Thursday is the cheapest day to fly to Europe, Wednesday to North America and Monday for Africa if you're leaving from the UK.
The return flight also changes depending on where you've been. Flights from South America and the Middle East are cheapest on Monday, form Europe it's Sunday and from North America it's Tuesday.
The cheapest days to fly:

Source: KAYAK