December 20, 2019 Hartsfield-Jackson International Airport : Spirit Guest Service Agent, Dante Stroud (left) sported a Santa's hat as he helped customers on Friday, Dec. 20, 2019 at Hartsfield-Jackson International Airport. The Transportation Security Administration will screen some 42 million passengers at airport security checkpoints nationwide over the holiday travel season that began Dec. 19 and runs through Jan. 5. The forecast for crowds going through airports during that period is up 3.9 percent from a year ago and averages 2.6 million passengers a day. Travelers should allow extra time to get through security screening and ensure that they donât bring prohibited liquids, weapons or other restricted items through checkpoints. The busiest days are expected to be Friday Dec. 20, Saturday Dec. 21, Friday Dec. 27 and Thursday Dec. 26. The least busy days are expected to be Christmas Eve, New Yearâs Eve and Christmas Day. The busiest day on record nationally for the Transportation Security Administration was Dec. 1 this year, the Sunday after Thanksgiving, when TSA screened more than 2.8 million travelers. JOHN SPINK/JSPINK@AJC.COM