February 29 is a date that usually occurs every four years, and is called leap day. This day is added to the calendar in leap years as a corrective measure, because the earth does not orbit around the sun in precisely 365 days.
That is the shortened explanation of why we have to add an extra day to our calendar every four years. All the other information I read was way too much.
Do you have a Leap Year or Leap Day celebration?
We do not celebrate Leap Year or Leap Day,
but if we did I am sure the theme would include frogs.