(in the Gregorian calendar) a year that contains 366 days, with February 29 as an additional day: occurring in years whose last two digits are evenly divisible by four, except for centenary years not divisible by 400.
a year containing an extra day or extra month in any calendar.
The additional day in a leap year keeps the calendar in sync with the seasons.
The formula is a true yield annualized calculation, which is also adjusted to reflect leap year, when necessary.
The program knows which years are leap years and will display a check-mark to denote a leap year.
Many published algorithms ignore the leap year cycle and treat each year as any other year.
British Dictionary definitions for leap year
a calendar year of 366 days, February 29 (leap day) being the additional day, that occurs every four years (those whose number is divisible by four) except for century years whose number is not divisible by 400. It offsets the difference between the length of the solar year (365.2422 days) and the calendar year of 365 days