We use a free program, picture timeclock that is on one computer and the employees clock in and out. It calculates their hours easily. Pretty basic, but it works. The company gives it away probably so you may be interested in their other products.
I have no financial interest, the web site is:
http://www.workschedules.com/Pclock.htm


Wendell
Pediatrician in Chicago

The patient's expectation is that you have all the answers, sometimes they just don't like the answer you have for them