Lydia, who was sitting upside down in an old recliner next to her mother, sighed. “Daddy,” she said, “How long is it until my birthday?” I glanced at a calendar and did some quick math. “One week and four days from now.” She cheered and tumbled sideways out of the chair. Then she scampered back up onto the overstuffed arm like a squirrel that had fallen into a lake. While she panted with excitement I continued, “But I have some bad news,” still looking at the calendar. “What’s that?” She was upside down again, her legs frantically riding an invisible bicycle. “Well, I’m sorry to tell you, but this year your birthday is on a Monday.” She fell over sideways again with a terrible…