Holiday travel is just around the corner. And if you're thinking about booking a trip you probably start by searching Google Flights, right? Well, Google just published five years' worth of airfare data from one of the most popular travel tools online to help us on our quest for cheaper tickets.

The research actually supports some old school travel myths—like it's cheaper to fly in the middle of the week than on the weekend. But there are also some results that may surprise well-informed travelers—like prices for domestic flights are lowest between 21 and 60 days out.

According to By the Way, the engineers looked at average round-trip airfares between Aug. 1, 2017, and Aug. 1, 2022, from 4,000 cities in the United States. For the holidays, their data showed that you don't have to lock something down a year in advance, but you shouldn't wait until the last minute. They suggest looking for Thanksgiving flights within 36 to 74 days ahead of time (which basically means you should start shopping for tickets over the next few weeks).

The lowest average prices for Christmas showed up 22 days beforehand—but it might be too stressful to wait until December to book. Phil Dengler, co-owner of the travel site The Vacationer says it's a risk and you should give yourself a hard deadline before Thanksgiving to avoid shelling out hundreds of extra dollars. Plus, there are other considerations to take into account as well, of course. Like how crowded the airports will be. The Hill has a list of dates for the lowest cost and smallest crowds.

Non-stop flights are found to be, on average, about 20% more than connecting flights, but flights with stops also increase the risk of interruptions—which have become more common lately. A recent poll by the travel insurance company World Nomads found that more than one in three respondents had spent anywhere from $250 to $1,000 on flights, meals or hotels because of flight delays or cancellations this summer.

Personally, when I'm on Google Flights, I like to use the tool's “explore” feature. Just add the preferred travel dates, which can be as specific or flexible as you want, input your home airport, and hit the search button. It finds great deals on destinations (both flights and hotels) and you can book them right then and there—for now. According to Travel + Leisure, Google will stop offering the option to book a flight directly through the site in March of next year.