Function Problems

Calculate Working Days Until or After a Project Deadline in Excel

Maira Mehtab Sep 22, 2026 868 views

Question details

The user needs an Excel formula to calculate the exact number of working days remaining until a deadline (as a negative number) or the number of days a project is overdue (as a positive number), specifically excluding weekends and designated holidays.

Product: Excel
Device & OS: not provided
Scenario: Tracking project timelines and computing accurate days remaining or overdue for active tasks.
Observed behavior: The standard date calculations might result in an off-by-one error because the default function includes both the start and end dates in its total count.

Before you start

Ensure you have a designated column or range in your spreadsheet that lists all custom holidays, as standard functions only exclude default weekend days.

Solution 1Recommended

Use the NETWORKDAYS Function with an Adjustment

Utilize the NETWORKDAYS function to find the difference between the deadline and the current date, subtracting 1 to adjust for the inclusive date calculation.

The NETWORKDAYS function is designed to return the number of whole working days between a start date and an end date. It automatically excludes Saturdays and Sundays, and can exclude custom holidays if provided.

However, because the function includes both the starting and ending dates in its calculation, calculating the difference between two dates might yield a number that is one day too high for standard overdue calculations. Subtracting 1 corrects this behavior.

Set Up Your Date References

Ensure your project deadline date is in one cell (for example, A2) and the current status date or today's date is in another cell (for example, B2). Place your list of custom holidays in a separate range, such as D2:D10.

Enter the Base NETWORKDAYS Formula

In your designated result cell, begin by typing the formula `=NETWORKDAYS(A2, B2, D2:D10)`. This will calculate the total working days between the two dates, excluding your specified holidays.

Subtract 1 for Accuracy

Modify the formula to `=NETWORKDAYS(A2, B2, D2:D10) - 1`. This adjustment corrects the inclusive counting behavior, ensuring you get an accurate negative number for days remaining or a positive number for days overdue.

Handle Missing Dates with an IF Statement

To return a blank cell when the required date conditions are not met (e.g., the cell is empty), wrap your formula in an IF function: `=IF(OR(A2="", B2=""), "", NETWORKDAYS(A2, B2, D2:D10) - 1)`.

Understanding Inclusive Dates: For example, from January 22 to January 25, NETWORKDAYS counts four days (22, 23, 24, 25). Subtracting 1 provides the strict difference in days between the two dates.

Manage Projects Efficiently

Calculate Project Deadlines Easily in WPS Spreadsheet

WPS Spreadsheet provides full support for advanced date and time functions, including NETWORKDAYS, allowing you to accurately track project timelines, deadlines, and working days with ease.

1. Open Your Project Tracker: Launch WPS Spreadsheet and open the workbook where you track your deadlines.
2. Access Date Functions: Click on the cell where you want the calculation, go to the Formulas tab, select Date & Time, and choose NETWORKDAYS.
3. Input the Parameters: Select your start date, end date, and highlight your custom holiday range.
4. Apply and Drag: Add '- 1' to the end of the formula in the formula bar, press Enter, and drag the fill handle down to apply it to all your projects.

Fully compatible with Microsoft Excel formulas and date functionsBuilt-in templates for project management and deadline trackingLightweight and fast calculation for large datasetsFree to use across multiple platforms (Windows, Mac, Mobile)

microsoft office alternative - wps office

Frequently Asked Questions

Why does NETWORKDAYS return a number that is one day higher than expected?

NETWORKDAYS calculates the total number of working days inclusive of both the start date and the end date. To get the strict mathematical difference in days between the two dates, you must subtract 1 from the final result.

How do I account for specific company holidays in my calculation?

You can list your specific holiday dates in a separate column or range. Then, add this range as the third, optional argument in the NETWORKDAYS function, formatted as =NETWORKDAYS(start_date, end_date, holiday_range).

How can I calculate working days if my weekend is not Saturday and Sunday?

If your workweek uses different weekend days, use the NETWORKDAYS.INTL function instead. This function allows you to specify exactly which days of the week should be considered non-working weekend days.

How do I make the cell appear blank if the deadline date is missing?

You can wrap your NETWORKDAYS formula in an IF statement to check for blank cells. For example, using =IF(ISBLANK(A2), "", NETWORKDAYS(A2, B2)-1) will leave the cell blank until a date is entered in cell A2.

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