Question

how is leap year calculated

Answer 1

To eliminate this error, the Gregorian calendar stipulates that a year that is evenly divisible by 100 (for example, 1900) is a leap year only if it is also evenly divisible by 400. For this reason, the following years are not leap years: 1700, 1800, 1900, 2100, 2200, 2300, 2500, 2600.

Answer 2

If the year is evenly divisible by 4, go to step 2. ...

If the year is evenly divisible by 100, go to step 3. ...

If the year is evenly divisible by 400, go to step 4. ...

The year is a leap year (it has 366 days).

The year is not a leap year (it has 365 days).