It's February 29, 2008 today, a leap day because 2008 is a leap year (instead of a common year). The pseudocode to determine whether a year is a leap year or not:
if (year modulo 4 is 0) and ((year modulo 100 is not 0) or (year modulo 400 is 0)) then leap else no_leap
I was about to write some code in C# with the same functionality when I discovered that this is out-of-the box functionality available in the .NET Framework. Just call the System.DateTime.IsLeapYear(int year) method.
But anyway, here is the C#:
1: public static bool IsLeapYear(int year)
2: {
3: if (year % 4 != 0)
4: {
5: return false;
6: }
7: if (year % 100 == 0)
8: {
9: return (year % 400 == 0);
10: }
11: return true;
12: }