Formula to Account for Weekend Days for an SLA

Hi, I need some help trying to figure out the best way to calculate the weekend days for a service level agreement. It's for a radiology center. The center has an SLA with radiologists to interpret images within 1 business day from the date the images are uploaded to the radiology system. Many of these radiologists work on the weekends. Sometimes they will get images uploaded on a Friday and will interpret on the weekend. Or, images uploaded on Saturday or Sunday and interpreted on Monday or Tuesday. An image uploaded on a Friday or Saturday but interpreted on a Monday is still 1 business day. Then there are federal holidays to take into account but I can put that aside if it's too complicated. I need a formula that will subtract the days of the weekend but I'm not sure how to go about it. I attached an example of the spreadsheet and would appreciate some input.

Try using the networkdays formula =NETWORKDAYS(start_date,end_date,[holiday])


Start_date, end_date: the date range that you want to count workdays from.

Holiday: optional, the cell range that contains the holiday dates that you want to count days excluding.

Hope that helps.

Thanks! I didn't even know that function existed. Handles holidays too!

This formula produces some odd results. Look at these cases:

Upload Interp UpDoW IntDoW Days
5/24/2024 5/27/2024 Friday Monday 1
5/24/2024 5/27/2024 Friday Monday 1
1/12/2024 1/15/2024 Friday Monday 1
5/24/2024 5/27/2024 Friday Monday 1
11/8/2024 11/11/2024 Friday Monday 1
2/10/2023 2/13/2023 Friday Monday 2
8/11/2023 8/14/2023 Friday Monday 2
8/18/2023 8/21/2023 Friday Monday 2
9/22/2023 9/25/2023 Friday Monday 2

These are all cases where images are uploaded on a Friday and interpreted on a Monday.
This would be equivalent to interpreting on the same day or at worse, 1 day.
So we'd need to subtract the weekend. But why does it return a 2 for some?

Have a look at the V2 file I uploaded. It's got all the deidentified data. It's filtered to show upload days = Friday and Interp days = Monday, Tuesday or Wednesday.

What's the difference between ID 632 and 633? Both were uploaded on a Friday and interpreted on the Monday. Yet 632 says it's 1 workday and 633 says it's 2.

Images that get uploaded on a Friday and interpreted on Saturday or Sunday should be considered "same day" or 1 workday. Images uploaded on a weekend and interpreted on Monday should be considered same day or 1 workday, Tuesday would be 2 workday and Wednesday would be 3 workdays.

Does my logic make sense?

Just did. It has all the de-identified data.

Where you are getting '1', the formula is taking off an additional day because you have set one of those days as a holiday.

OK but If I want to make Friday-Monday 1 day, should I just subtract 1 day?

yes as simple as that (=NETWORKDAYS(start_date,end_date,[holiday])-1). If you apply that to the whole column it will take one day off each of the calculations. So Monday to Friday will become 4 working days (assuming no holidays also being taken off!) The formulas includes both the start and end days in its calculation. You can explore =NETWORKDAYS.INTL() for other options if needed.