Include Saturdays And Maybe Sundays

currently I'm working as project manage for a software development studio and I am using MS project for all my work. Since the development team aren't aloud to have a MS project license on their PC I have to copy their tasks from MS project and put them into Excel.

I would say that I am okay using Excel but not an expert. I want to create a formula that uses NETWORKDAYS to determines a finish date from a duration and start date.

The headers I would use for each column are Duration, Start and Finish. So I would like to be able to get a team member to put a duration down i.e 1 day and give me the start day and in the finish date it produces a finish date automatically without including Bank Holidays and Weekends. What would the formula be for that?

I have the same question as Madball and was able to work out the Worday function, however for my company, we work on Saturdays and or Sundays sometimes.

I would like to be able to specify from line to line if Saturday or Sunday needs to be included in the duration calculation resulting in a finish date, however if I can simply get one formula to work that includes Saturdays alone (most common working day of the weekend, and do work more than don't) it would be the most helpful, I think I can get it adjusted from there.