Schrikkeldag

"What you celebrate on your birthday isn't the annual arrival of your birth date; it's the fact that you're one year older. One year = one complete revolution by the earth around the sun = 365 days, 5 hours, 48 minutes, and 46 seconds. To figure the right day to celebrate your birthday, you add 365 and one-quarter days to the hour of your birth. Suppose you were born February 29, 1972 at 10 PM. Then 365 and one-quarter days went by and behold, the first anniversary of your birth hour came on March 1, 1973, at about 4 AM. The second and third anniversaries also fell on March 1, at 10 AM and 4 PM respectively. Comes year four (1976), and your anniversary is back where it started, February 29 at 10 PM. Things would have worked out differently if you'd been born at 4 AM on leap day. Your first, second, and third birth-hour anniversaries would have occurred on February 28 at 10 AM, 4 PM, and 10 PM, respectively. If you'd been born at 4 PM, your first anniversary would fall on February 28 but your second and third on March 1. What happens for leap-day babies born at other hours is left as an exercise for the student."

(bron: http://www.straightdope.com/)

Weer wat geleerd! ;)