Step-by-step explanation:
What is the day of the leap?
In the four-year cycle, an extra day is added to the calendar. Adjustments to ensure that our calendar is always in sync with the time the earth needs to be in front of the sun. Specifically, the Earth orbit lasts 365 days, 5 hours, 48 minutes and 46 seconds.
This extra 5+ hours is combined over time, so after four years, another day is added - the day of the leap - to our calendar with the sun.
When is the day of the leap?
Hell Day is February 29th. Why February? Because one of the goals of the calendar is based on the solar year, the Easter holiday in the spring. To do this, the calendar is set, so the vernal equinox is always on or near March 21st.