How to Use the NETWORKDAYS Function in Excel

The NETWORKDAYS Function

1. Set up your start date and end date columns

• Identify the earlier date as the start date
• Identify the later date as the completion or end date
• Make sure both are stored as real Excel dates so the function calculates correctly

2. Use NETWORKDAYS to calculate business days between two dates

• Enter the NETWORKDAYS function
• Select the start date as the first argument
• Select the completion date as the second argument
• This returns the number of working days between the two dates while excluding standard weekend days

3. Confirm the result against the calendar

• Review the date range to make sure the count makes sense
• Notice that the function excludes Saturdays and Sundays automatically
• This helps verify that the output is showing business days rather than total calendar days

4. Add a holiday range to exclude company or public holidays

• Use the third argument in NETWORKDAYS to reference a holiday list
• Highlight the holiday cells you want excluded from the count
• This allows the calculation to remove holidays in addition to weekends
• Update the holiday list as needed based on your company schedule

5. Lock the holiday range before copying the formula down

• Use absolute referencing so the holiday list does not shift when you fill the formula down
• Press F4 after selecting the holiday range to lock it
• This keeps every row tied to the same holiday calendar

6. Test what happens when the holiday range is not locked

• Copy the formula down without locking the range
• Notice how the holiday reference moves and starts pulling the wrong cells
• This can create errors or inaccurate business day counts
• Locking the range prevents that issue

7. Add a project delay flag with IF and NETWORKDAYS

• Use the IF function together with NETWORKDAYS
• Compare the business day count against your delay threshold
• If the result is greater than the threshold, label the job as delayed
• Otherwise, label it as on time
• This turns the business day calculation into a quick operational flag

8. Adjust the delay threshold based on your process

• Set the cutoff based on your service standards
• The video shows using a number like 5 business days, but you can change it
• You can also decide whether the threshold should be greater than only, or greater than or equal to

9. Calculate the average completion time

• Use the AVERAGE function on the completed business day counts
• This gives you the average number of business days required to complete installs or repairs
• It is a simple way to summarize turnaround time across all jobs

10. Use NETWORKDAYS.INTL when weekends are different

• If your workweek does not follow the standard Saturday and Sunday weekend, use NETWORKDAYS.INTL
• This version lets you define which days count as the weekend
• It is useful when your operating schedule differs by region or company policy