I am confused.  It sounds like you want a string of some sort.  If you set the parameter to datetime, you get the Crystal Calendar control to aid in your selection.  If you want a drop down with dates and they correspond to data, you can use a dynamic parameter and populate the data from your data by adding a command (Database Expert) and selecting the dates from your data.  If you want a list of dates and it is of fixed length you can try something like: select getdate() union select datediff(day, -1, getdate()) union select datediff(day, -2, getdate()) in the command and make the parameter dynamic.