The "is Between Dates" selected date will always be 00:00:00
So for example, if you select from September 23 to September 23 you are selecting 2015.09.23 00:00:00 - 2015.09.23 00:00:00, so it's the same time.
If you want to see everything happen on the full 24 hours of 23rd September you will need to select from September 23 to September 24.
If you have an Incident that has been logged exactly on 00:00:00 then I don't think these criteria is the way to go.
You can instead then use "Is Between" which I believe will allow you to select a time as well.