That project knows a year is leap or common. The rules for a number to be leap: 1- It should be evenly divisible by 4, e.g. 2020, 2024, 2028 2- It should NOT be evenly divisible by 100, e.g. 1900 is common 3- It should be evenly divisible by 400, e.g. 2000, 2400 Any year not applying any of the rules above is common, and can't be said to as otherwise in any circumstences on the multiverse!!!
