Flying around the holidays isn't cheap, but if you fly on Thanksgiving Day or Christmas Day (November 22 and December 25, respectively), you can save hundreds of dollars.

"Flying on Thanksgiving and Christmas Day is largely a reflection of supply and demand," Kevin O'Leary, senior analyst at Priceline, tells CNBC Make It. "More travelers fly the days prior to Thanksgiving and Christmas than on the day itself, and fares reflect this."

O'Leary analyzed Priceline's historical pricing data from 2017 and found that travelers who arrived on Thanksgiving Day or Christmas Day yielded the best flight deals overall. Travelers paid approximately $100 less per ticket on average.

"We expect similar savings to be available this year," he says.

For example, a recent Priceline search from New York City area to Atlanta, flying on Thanksgiving Day (one way) is $121. On Nov. 21, it is $266. On Nov. 20 it is $166.

If you're willing to fly on the holidays, there is also an optimal time to purchase your ticket.

"Priceline's historical data and current pricing trends suggest that ... the very best days to book are Tuesday, Oct. 23, for flights arriving on Thanksgiving, and Thursday, Oct. 18, for flights arriving on Christmas Day," O'Leary says (though flight prices and savings will differ depending on the route).

"We recommend you begin your search as soon as possible to give yourself the best chance of finding the ideal flight for your plan and budget."

Of course, pricing also depends on where you're going. Priceline determined the least expensive destinations to travel for Thanksgiving and Christmas Days based on 2017 and 2018 average one-way ticket prices. Here they are: