March 14 is Pi Day, an annual celebration of the mathematical constant of pi, representing the ratio of a circle's circumference to its diameter. The holiday is observed on March 14 or 3/14 because 3.14 are the first three digits of the infinite number pi — 3.14159 ... and on and on.

For two days only, on March 13 and 14, CPK Rewards members can get an Original BBQ Chicken, Pepperoni, or Traditional Cheese pizza for $3.14 with any purchase of $25 or more. Non-members can enroll in CPK Rewards on CPK.com or on the CPK app anytime through March 14 to get the deal, which is available for dine-in, takeout or delivery.