Extract time as a positive value from Date/Time Stamp, to use for calculating

[DubCap01]

Hi everyone in the Source of All Knowledge

I have a table with many events created over a period of a month, so there's a date/time field relevant to each event. Within this date field is of course the full date/time stamp of the event creation. I can view it as 24-Mar-15, 24/03/2015 8:29pm, 8:29pm or 42087.85397 and you all know the rest.

What I am trying to achieve is to extract the 8:29pm value so I can group it in one of either three time brackets, which are 7am-9:29am; 9:30am-5:59pm and; 6:00pm-22:59pm. So, I need to drop the DATE element.
Then, using that value (and the values of all the other events within that month, group them together so I can report that n events occurred in the first time bracket, n events occurred in the second, and so on.

Just not sure how to extract the time value so I can calculate with it.

Anybody got any clues please?

Thanks very much in anticipation


Pete

[DubCap01]

going to re-ask this question in another format, therefore closing this question