In this year’s U.S. holiday shopping season, the highest number of store visits will occur on Black Friday, according to Sensormatic. Second will be the Friday before Christmas, Dec. 23, and third will be the day after Christmas.

On average, the 10 busiest shopping days account for 40% of all U.S. holiday retail traffic, according to the company. However, shopper numbers might consolidate further into those 10 days as shoppers try to make fewer trips in order to save on gas.

“Historical data will be extremely valuable in determining how to stock, staff and promote deals during the holidays,” said Sensormatic global leader of retail consulting and analytics Brian Field. “Christmas Day falls on a Sunday this year, so the last Saturday before Christmas is technically Christmas Eve, shifting the landscape somewhat from the norm. As most stores close earlier on the 24th and potential shoppers begin their holiday festivities, the 17th is likely to be the busiest Saturday in December. The last time this happened was in 2016, and if that’s any indication of what will happen this year, retailers can expect bigger crowds and higher-than-normal demand on this day than they might have in other years. They’ll need to plan their approach accordingly.”