 APC research has shown that Apple is Americans' favorite pie, that 59% of Americans consider pie an appropriate late-night snack, and that 20% of Americans have eaten an entire pie.National Pie Day, which is held annually on January 23, is now sponsored by the APC since 1986.The holiday was started in the mid-1970s by Boulder, Colorado teacher Charlie Papazian after he declared his birthday to be National Pie Day.