Definition of leap day in English:
The intercalary day in a leap year; 29 February.
- So every four years a leap day is added to the calendar to allow it to catch up to the solar year.
- If a leap day is added every fourth year, the average length of the calendar year is 365.25 days.
- A leap week calendar cannot use the same rules for the leap week as leap day calendar uses for the leap day.
Definition of leap day in:
- US English dictionary