In the previous blog entry, 3. Are You Odd?, I referred to determining a leap year still being a manual programming process in many cases. There are certainly umpteen library functions out there to do it, but it's simple to do and a nice programming exercise for function writing.
How does one determine if a given year is a leap year? It's a common belief that if the year is evenly divisible by 4, that it is a leap year. That is true most of the time, but not always.