Thursdays are the busiest days to fly, but travelers taking to the skies on Mondays could save about 15 percent off the cost of their domestic trip. When it comes to international flights, travelers can save by departing on a Saturday.

The data, which was shared with Travel + Leisure, comes from Expedia’s Fall Travel Outlook and can help travelers plan ahead to make the most of their shoulder season getaways.

Overall, the week of September 1 is expected to be the most affordable for domestic travel with ticket prices coming in nearly $100 cheaper than during the peak of summer. For international flights, travelers should consider booking the week of October 20 when the average ticket is nearly $260 lower than summer. 

“Regardless of the destination, fall is a fantastic time to travel and there’s still time to plan a getaway,” Melanie Fish, the head of Expedia Group Brands public relations, said in a statement shared with T+L. “The week following Labor Day is the best time for domestic airfare deals, while Oct. 20 is the best for international trips — and for the start of leaf-peeping season.” 

To avoid crowds, reconsider traveling during the week of September 8, which is expected to be the busiest week of the fall travel season. Instead, book during the week of November 10 — just over two weeks before Thanksgiving — since it is expected to be the lightest.

In general, traveling during the fall shoulder season can be a budget saver. In fact, Expedia noted airfare historically drops by 10 percent compared to the summer.

That’s even more true for certain destinations like Honolulu and Seattle, which are seeing a drop in average ticket prices of 15 percent or more. Or save big on a warm weather escape to Santo Domingo in the Dominican Republic, which is seeing a 25 percent drop in average ticket prices compared to summer.

Regardless of where travelers go, there are plenty of great shoulder season getaways from beach escapes to hunting for fall foliage, European jaunts, and more.