User-defined scalar functions (scalar UDFs) are tools that can simplify access to real and contrived date and time data for the end user. In my September TSQL-Tutor article "Datetime for Durable Databases," InstantDoc ID 26170, I demonstrated how to put together a simple scalar UDF that you can use with datetime values. Now, let's look at the ways you can use UDFs to handle more complex date and time data. One opportunity for using a UDF arises when your data is a date and time value but it isn'...