Happy National Pancake Day! To celebrate the occasion, IHOP is offering each customer a free short stack of its signature buttermilk pancakes today from 7 a.m. to 10 p.m. (That gives you 15 hours to find the restaurant closest to you.) Customers are also invited to make a voluntary donation – those made at restaurants the Seattle area will benefit the Children’s Miracle Network Hospitals’ program at Seattle Children’s Hospital.