When you play a match early (out of order) you have 2 options in TennisPoint:
Change the date in the “edit schedule” page to the actual date in which are you playing the match. FYI, the "match number" is still preserved since that is the official match number in the league (ALTA, USTA, etc) as well.
If your playing early but each line is playing on different days/times it is recommended to activate “rain mode” for the match lineup (only available after you create a lineup) -- this way each line can specify their own date/time & location. For more details around rain mode, here is a blog article detailing more info: http://blog.tennispoint.com/2009/09/24/rain-mode-available-now/