One function which is often requested from my archived blog posts is dbo.FriendlyDateDiff.
The Function takes two DateTimes and a requested biggest Dimension like days / hours etc.
A sample would be calculating the datediff between My birthdate and the current date:
@Startdate = '19780619 15:15:00', @EndDate = '20081103 19:33:16', @BiggestDimension = {PlaceTheDimensionHere}
(Should be something around thirty years ;-) )
Always impressive if you suprise your wife using your wedding day as a starting date and the current date as the end date, using the 'Y' parameter value :-)
The function is as an attachment with this post. Feel free to use and distribute it.
-Jens