(if (= (mod year 100) 0)
"leap year is century years divisible by 400,
not other century years, otherwise anything evenly
divisble by 4"
(if (is-century-year year)
(if (= 0 (mod year 400))
(if (= 0 (mod year 4))
Friday, February 29, 2008
Here's a bit of elisp code to find out...