How calculate business days between dates

Mastering Business Day Calculations Between Dates in Excel

Learn how to accurately calculate the number of working days between two dates in Excel, excluding weekends and holidays, using powerful built-in functions.

Calculating business days between two dates is a common requirement in many professional settings, from project management to financial analysis. While a simple subtraction of dates will give you the total number of days, it won't account for weekends or public holidays. Excel provides specialized functions that make this task straightforward and accurate. This article will guide you through the primary methods for achieving this, focusing on the NETWORKDAYS and NETWORKDAYS.INTL functions.

Understanding NETWORKDAYS

The NETWORKDAYS function is Excel's standard tool for calculating the number of whole working days between two dates. It automatically excludes Saturdays and Sundays and can optionally exclude a specified list of holidays. This function is ideal for scenarios where your workweek is Monday through Friday.

=NETWORKDAYS(start_date, end_date)

Basic syntax for NETWORKDAYS, calculating working days between two dates, excluding weekends.

To include holidays, you'll need a range of cells containing your holiday dates. For example, if your start date is in cell A2, end date in B2, and holidays are listed in cells D2:D10, the formula would look like this:

=NETWORKDAYS(A2, B2, D2:D10)

Using NETWORKDAYS with a specified range of holiday dates.

Advanced Control with NETWORKDAYS.INTL

For more flexible workweek definitions, Excel offers NETWORKDAYS.INTL. This function allows you to specify which days of the week are considered weekends, rather than being limited to just Saturday and Sunday. This is particularly useful for businesses with non-standard work schedules or international operations.

=NETWORKDAYS.INTL(start_date, end_date, [weekend], [holidays])

Syntax for NETWORKDAYS.INTL, including optional weekend and holiday arguments.

The [weekend] argument can be either a number or a string, defining which days are weekends. Here are some common numeric codes for the [weekend] argument:

Common Weekend Codes for NETWORKDAYS.INTL

For example, to calculate business days between A2 and B2, excluding Sunday and Monday as weekends, and D2:D10 as holidays:

=NETWORKDAYS.INTL(A2, B2, 2, D2:D10)

Calculating business days with Sunday/Monday as weekends using NETWORKDAYS.INTL.

Visualizing the Calculation Logic

To better understand how these functions operate, let's visualize the decision process Excel follows when calculating business days.

Flowchart of Business Day Calculation Logic

1. Step 1

Step 1: Define Start and End Dates. Clearly identify the beginning and end of the period you want to analyze. These should be in a valid date format in your Excel sheet.

2. Step 2

Step 2: Identify Your Workweek Pattern. Determine which days of the week are considered working days and which are weekends. For standard Monday-Friday, NETWORKDAYS is sufficient. For custom patterns, NETWORKDAYS.INTL is required.

3. Step 3

Step 3: List All Holidays. Create a separate range or list of all public or company-specific holidays that should be excluded from the business day count. Ensure these are also in a valid date format.

4. Step 4

Step 4: Apply the Correct Formula. Choose either NETWORKDAYS or NETWORKDAYS.INTL based on your workweek definition and arguments. Reference your start date, end date, and holiday range correctly.

5. Step 5

Step 5: Verify the Result. After applying the formula, manually check a few simple date ranges to ensure the calculation aligns with your expectations, especially around holiday periods.