leap day
bissextile day
February 29

Also that 366 days would be a full year even if a leap day was included.

To compensate for this, three leap days must be omitted every 400 years.

The leap day was introduced as part of the Julian reform.

I arrived here almost exactly six months ago, on leap day, timing that seemed appropriate enough to me.

Systems of leap days usually do not affect the week cycle.

The plan was to skip all leap days in the period 1700 to 1740.

That is similar to the idea of a leap day.

She was one of few people born on a leap day to celebrate a centennial.

A leap day is added to February every four years.

This will be the first instance of a full moon on a leap day since 1972.