Friday, March 24, is National Cheesesteak Day. And Philadelphia International Airport (PHL) is celebrating with a weeklong tribute of specials and giveaways. Through March 24, the promo code “CHZSTK23” offers $3 off a cheesesteak or cheesesteak-inspired menu item from participating locations at OrderAtPHL.com. Then on National Cheesesteak Day, Friday, March 24, PHL travelers will be treated →