The elusive February 29th rolls around again this year, as it does in all years that are divisible by four — unless, oddly, they are years that are divisible by 100 but not by 400! This quirky adjustment to the calendar has its origins in an astronomical and mathematical reality. While ordinary years operate on the assumption that the earth takes 365 days to revolve around the sun, the reality is not so neat. A solar year, in fact, takes about 365 days and six hours to complete. With a mix of astronomy and math, check out the Catholic origins of Leap Day/Year: https://cruxnow.com/church-in-the-usa/2020/02/leap-years-extra-day-has-a-catholic-origin
