Photo: Mizina / iStock / Getty Imagesusatoday.com; National Pi Day 2024: Get a deal whether you prefer apple, cherry or pizza pie It may not be in your calculations for Thursday, March 14, but it's National Pi Day. Blaze Pizza, Papa John's, DoorDash and others have pizza deals. Taco Bell has a special on its Mexican Pizza, too.; Mike Snider, Amaris Encinas; March 14, 2024