How many leap years since 1956?

To determine the number of leap years since 1956, we first identify the leap years from 1956 to 2023. Leap years occur every four years, so the leap years in this range are 1956, 1960, 1964, 1968, 1972, 1976, 1980, 1984, 1988, 1992, 1996, 2000, 2004, 2008, 2012, 2016, and 2020. This totals 17 leap years.