After a long holiday season spent arranging flights and schlepping to and from the airport, travel may be the last thing on your mind. But the post-holiday slump that falls on this part of the calendar is exactly what makes it the perfect window for finding great deals on airline tickets. As Travel + Leisure reports, flights purchased for trips happening within the next six months are cheapest during the first two weeks of January.

That data comes from a recent analysis by Skyscanner. After looking at monthly searches from over 60 million users, the flight search engine determined that the first two weeks of this month will feature the lowest airfare prices of the year. Travelers who wait until March to book their trips risk paying up to 13 percent more for domestic flights, while the prices of international flights could become 56 percent higher than the year-round average by that time.

If two weeks isn’t enough time for you to commit to a trip, it’s fine to wait a little longer to take the plunge. According to trends from past years, travel costs will remain lower than average until around February 15, at which point they will start to rise quickly.

January is typically the most affordable month to book flights, but exactly how much you can save varies from year to year. In January 2016, airfares were the lowest they’d been in years, with both discount and major airlines offering some round-trip domestic flights for less than $100. It’s too early to say whether this January will be more or less expensive than previous years, but it doesn’t hurt to browse prices and start planning your dream vacation now.

[h/t Travel + Leisure]