If the above is not something you can do you need to figure out how to have a comparative value to logically determine if the date has changed. Without having a piece of data that you can use to flag if the change occurred there is no condition to change the font on.
If you are comparing one row of data to the next rather than having a "flagged" column in tha row you could take the route of (as DC mentions) can you compare one record to the next like below?...
making sure your data is sorted correctly so that you can properly compare previous records, change your font where the "previous(date)<>date" or any combination of previous fields being the same or not the same like "previous(ID)=ID and previous(date)<>date"
Edited by DBlank - 07 Apr 2009 at 8:41am