Leap day?

What does one call February 29th? The years that have February 29th are called Leap Years, but what is the actual day? Leap day? Sounds odd, Happy Leap day! ;P

On "Leap Day" I actually learned why we have an extra day every 4 years. It turns out that it takes the earth about 365 days and 6 hours to rotate once around the sun. Thus, every four years those leftover 6 hours from each day make up a full 24 hour day! If we didn't add an extra day, then eventually seasons wouldn't match up with our calendar dates.

This is the day,

This is the day,

That the Lord has made,

That the Lord has made.

Let us rejoice,

Let us rejoice,

And be glad in it.

And be glad in it. ;D