extract time from date/time for sorting

Hi all,

Have a data dump that puts the date/time in a cell together (5/23/11 12:41 AM), which I need in one place so that everything is in order of the actual time it came in, but I also want to run a chart based on the time of day (hour) disregarding the dates. Even if it's formatted as HH:MM only, it still sorts by day. How can I make the data sort by time, regardless of the date in the cell? I can add another column, but I don't know how to pull only the hh:mm info out of the date cell. Alternatively, is there a way to sort the data in a chart without sorting it in the generating table?

Thanks!