How should I calculate working hours between two dates? Say if start at 9/25/2009 7:26:13 PM and finish at 10/20/2009 9:46:13 AM, the function should return 245:20:00 because the working hours are from 8am to 11 PM (8 - 23), and there are weekends between the dates. Preferably the function should work like the NETWORKDAYS() function, but it should also include the time, not just the dates. And also how can I exclude holidays if there are any.