Searching by date on the speaking page doesn’t work.
I’ve searched for conversation from the 09/15/2011 to the 09/15/2011 and 7:00AM to 7PM.
The result shows conversations from 2008, 2009 and so forth.
i had the same problem too. I found that if you ignore the date and just type in the time everything will be working properly.
This should now be working properly. Let us know if you experience any other issues related to this.