
Can you imagine only having your birthday every four years?? It's true! It's called leap year.
Leap year is one extra day on the calendar every four years. February 29th!
People that have their birthday on Feb. 29th have to look out for every four years.
Why on earth does that need to happen? The calendar is supposed to match the solar year-- in other words the length of the tim it takes earth to orbit the sun once but things quite that simple. it (actually takes earth 365 days,5 hours, 48 minutes, and 46 seconds to complete it's orbit about 3651/4 days). those extra hours gradually add up so that after years the calendar is out of step by one day adding a day every four years allows the calendar to mach up the solar year again.
(source: Meredith Tennant for KidsKnowit Network)