Creating A Function To Determine If A Specified Year Is A Leap Year

In honor of today being February 29th I thought I would create a quick post to discuss how to create a user defined function to determine if any given year is a normal calendar year or a leap year.  Though there is likely not much of a use for this in any real world scenario, aside from adding this logic to a corporate calendar table or some other date based calculator, I really just thought this would be a fun exercise.

The following script will create a user defined function in your database.  The function will accept a single four digit year value and return a string stating whether the year specified is a leap year or a normal calendar year.

Note that the value being passed to the function is of datatype INT. The results will be displayed as a string which requires that the value be converted using either CONVERT or CAST.  However, if you wanted to modify this script to use it to assist in creating a calendar table or some other calendar based calculation, you can change the datatype and have it output a 1 or 0 based on the result.

Once the function has been created you can easily call it using the following script.  In this example I am calling it twice in order to demonstrate both results.

The results of executing this are displayed below:

isleapyear_results

As stated above, there are very limited uses for a script of this nature but if you’re just interested in how to create a basic user defined function and then call it, this may provide some useful insight.

Happy Leap Year 2016!