• Hi All

    Please note that at the Chandoo.org Forums there is Zero Tolerance to Spam

    Post Spam and you Will Be Deleted as a User


  • When starting a new post, to receive a quicker and more targeted answer, Please include a sample file in the initial post.

Project plan - calculating accurate working days


Hello all, hoping you can help with this query.

I have a project plan which has 30 odd tasks, for each task the user only needs to enter task, responsible, start date and duration (as in working days).

Some tasks are 2 days, some are 10, 25, one is even 40. My isse is calcuating the completion date based on the start date plus the duration.

For example, if task 1 starts on a Monday and takes 5 days, it's completed on the Friday...easy.

But if task 2 starts on a MOnday and lasts 8 days, it should end the following Wednesday, i.e. 8 working days later. But simply adding the 8 days to the start date would have the task ending on the following Monday as it includes the weekend days.

I've tried various ways including networkdays or if the end date is a saturday then add 2 days etc. nothing seems to work for all durations.

Any help would be great, thanks!


Excel Ninja
Staff member
Mr Hiboy

Have you tried the Workday Function

=WORKDAY(Start_date, Days, [holidays])

for your use you may want to use it as

=WORKDAY(Start_date, Days - 1, [holidays])

It is worth noting that you can also setup a list of public holidays (not weekends) and Workday can include that in your calculations

Have a read of Excel help for more details