They take Pi Day pretty seriously over in the heart of Harvard Square. The nerdy-yet-hilarious holiday is observed on Wednesday, March 14th to reflect the first three digits of π (3, 1 and 4, or 3/14 in date form). Even if you’re not a math geek itching to honor the mathematical constant, you can still take advantage of some fun Pi Day specials, courtesy of The Charles Hotel. Chef Peter Davis is baking plenty of pies at Henrietta’s Table to fulfill your need for round desserts, and the bar team at Noir Bar is crafting apple pie cocktails for the sweet drink lover. Planning to treat yourself to an overnight stay at the Cambridge urban oasis now or at some point in the next few months? Get 31.4% off your room reservation — select dates only, people — and see the details here.