Sql Server comes with a host of built in functions such as ISNULL, CONVERT and CAST. Now if that wasn't enough rope to hang ourselves with, as of Sql Server 2000 we gained the ability to create our own user defined functions. In this article I will be looking at the three main date functions DATEADD, DATEPART and DATEDIFF (there is a fourth called DATENAME but I want to get to the end of this article before you fall asleep so I decided to leave it for another date and time! And no it doesn't foretell the name of your future blind date so it's not as interesting as it sounds anyway) Then I will be combining all three in a user defined function of our own by which time our necks will be well and truly stretched