I often use ArcMap 10 to display dynamic text using the dataFrame time.
<dyn type="dataFrame" name="Layout" property="time" emptyStr="[off]"/>
The above might display something like
However what I really want to be able to do is add 1 day to the dataFrame time and display it. This way I can display a date range
2011/08/16 - 2011/08/17