This conundrum becomes even more relevant during Christmas, when hordes of people are traveling to see family or jetting off to faraway destinations.

We reached out to travel search engine Kayak to identify when you should be booking your holiday travel for maximum savings.

In order to find this data, Kayak looked at holiday flight prices from last year during the month of December. Here are the dates they recommend booking (and not booking) flights this year.

You’ll get the best deals on Christmas Eve or Christmas day.

For those who don’t want to or can’t take much time off for Christmas, flying just before or on the holiday is ideal. Last year, the cheapest roundtrip flight departed and returned on Christmas day, coming out to an average of $234. The next cheapest flight involved flying out on Christmas Eve and returning on Christmas day, which came out to around $346.

Those who have more vacation time should either fly in early and return home on Christmas or fly in on Christmas and return a few days later.

If you have more time to spare before the holiday, consider departing on the 20th or the 21st. The 2016 data showed that returning on Christmas day meant spending around $350 for a roundtrip flight. Another viable option involves leaving the 23rd and flying back on Christmas, which cost around $358 last year.

Or, you can tack more time onto the other side of your trip, staying for a couple days after the holiday. In 2016, flights departing on Christmas and returning on the 27th came out to around $338. Staying a day later and coming back on the 28th only increased the price to $352.

If you don’t want to fly on Christmas, you can still get a pretty good deal on the days before and after the holiday.

Last year, a roundtrip flight leaving on Christmas Eve and returning on the 26th cost about $359, which is only $13 more than flights that departed the same day but returned on the 25th.

If you can take a longer vacation, consider giving yourself an extra day and flying back on the 27th. In 2016, a flight departing on Christmas Eve and returning on the 27th cost $368.

Try to avoid flying out the 15th or 16th and returning on one of the three days after Christmas.

The priciest flights last year were those departing nine or 10 days before the holiday and returning in the days just after the 25th. The most expensive combinations involved flying out on the 15th and coming back on the 26th or 28th, which cost around $644. Leaving on that same day but returning on the 27th cost about $610, whereas leaving a day later, on the 16th, and returning on the 28th cost $620.

Prices dropped for those who booked flights departing on the 16th and coming back on the two days after the holiday, but not by much. A flight leaving on the 16th and returning on the 26th came out to around $567. Returning on the 27th increased the price to $591.

source : http://www.thisisinsider.com/best-worst-days-christmas-travel-2017-12