2024 Leap Year Calendar. The julian calendar was 0.0078 days (11 minutes and 14 seconds) longer than the tropical year, so errors in timekeeping still gradually accumulated, according to nasa. Why do they happen and how often?
This extra day, february 29th, is inserted to maintain alignment between the calendar year and the astronomical year, which follows the earth’s orbit around the sun. The last leap day was in 2020.