Use exiftool's Filename and Directory tag based reorganization ability.
One example from there -- but feel free to research for your exact solution.
Exiftool is a powerful utility.
exiftool -d %Y-%m-%d "-directory<datetimeoriginal" image.jpg
Move 'image.jpg' into a directory with a name given by DateTimeOriginal, in the form '2006-03-27'.
You might want to use something like
%Y-%m-%d-%H to organize by the hour and then merge your hours. Or, you might rename your files with a suffix
%Y-%m-%d-%H%M and then sort them out for the 10:30-12:00 time window.
Update: Check PhotoMove 2.5 it is based on exiftool and referred from its homepage.