Daygroups & Reverse

Is it possible to sort the daygroups in reverse order (newest at the top) but 
to have the messages within the 
daygroup sorted in chronological order (oldest at the top)? e.g.,

 Friday, Sep 8
  * Meeting today, Eric P., 02:00
  * Re: Meeting today, Fred L., 07:00
  * Re: Meeting today, Tom B., 08:30
  * Re: Stockmarket down today, Tom B., 08:30
 
 Thursday, Sep 7
  * Stockmarket down today, Eric P., 09:00
  * Is it Friday yet?, Tom B., 09:30

...and so on.

Eric P.
SunPS Web Infrastructure Team