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Calculate a Project End Date in Excel

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Excel NETWORKDAYS.INTL Function Text-only Tutorial
Calculate the Number of Days Between Two Dates in Excel

Calculate the Number of Days Between Two Dates in Excel

© Ted French

Note: If you have limited experience with Excel try the ExcelNETWORKDAYS.INTL Function Step by Step Tutorial which includes detailed information about using this function.

This tutorial is intended for users familiar with using Excel's date functions.

Excel NETWORKDAYS.INTL Function Text-only Tutorial

Note: This function was first introduced in Excel 2010.

The NETWORKDAYS.INTL function is used to calculate the number of whole business or working days between the start date and end date of a project.

Days specified as weekend days are automatically removed from the total. In addition, specific days, such as statutory holidays, can be omitted as well.

Unlike the NETWORKDAYS function, the NETWORKDAYS.INTL allows you to specify which days and how many are considered weekend days rather than automatically removing two days per week - Saturday and Sunday - as weekend days.

The NETWORKDAYS.INTL Function's Syntax and Arguments

The syntax for the NETWORKDAYS.INTL function is:

= NETWORKDAYS.INTL ( Start_date, End_date, Weekend, Holidays )

Start_date - (required) the start date of the chosen time period. Enter the actual date for this arguments or the cell reference to the location of this data.

End_date - (required) the end date of the chosen time period. As with the Start_date, enter the actual end date or the cell reference to the location of this data in the worksheet.

Weekend - (optional) the number of days and which days of the week considered to be weekend days. Enter the weekend number code or the cell reference to the location of this data (see the table of number codes on page 2 of this tutorial).

Holidays - (optional) one or more additional dates that are excluded from the total number of working days. Use the cell references to the location of the data in the worksheet for this argument.

Example: Counting the Number of Days Between Two Dates

See the image above for help with this example.

Example details:

  • project start date - August 5, 2012
  • project end date - November 29, 2012
  • weekend days - Friday and Saturday so the number seven ( 7 ) will be entered for the Weekend argument
  • 2 additional holiday dates - August 19 and November 15 will be entered for the Holidays argument

Note: To avoid calculation problems that can occur if dates are accidentally entered as text, the DATE function will be used to enter the dates used in the function.

Entering the Data

  1. Enter the following data into the appropriate cell:
  2. D1:    Start:                          E1:    =DATE(2012,8,5)
    D2:    Finish:                        E2:    =DATE(2012,11,29)
    D3:    Weekend:                   E3:    7
    D4:    Holiday 1:                   E4:    =DATE(2012,8,19)
    D5:    Holiday 2:                   E5:    =DATE(2012,11,15)
    D6:    Number of Days: 
    
    

Entering the NETWORKDAYS.INTL Function

  1. Click on cell E6 to make it the active cell - this is where the results of the NETWORKDAYS.INTL function will be displayed

  2. Click on the Formulas tab

  3. Choose Date and Time functions > NETWORKDAYS.INTL from the ribbon to bring up the function's dialog box

  4. Click on the Start_date line in the dialog box

  5. Click on cell E1 in the worksheet to enter this cell reference into the dialog box

  6. Click on the End_date line in the dialog box

  7. Click on cell E2 in the worksheet to enter this cell reference into the dialog box

  8. Click on the Weekend line in the dialog box

  9. Click on cell E3 in the worksheet to enter this cell reference into the dialog box

  10. Click on the Holidays line in the dialog box

  11. Drag select cells E4 and E5 in the worksheet to enter these cell references into the dialog box

  12. Click OK in the dialog box to complete the function

  13. The number of working days for this project - 83 - should appear in cell E6 of the worksheet

  14. When you click on cell E6 the complete function =NETWORKDAYS.INTL( E1, E2, E3, E4:E5 ) appears in the formula bar above the worksheet

NETWORKDAYS.INTL Function Error Values

  • #VALUE! : occurs If one of NETWORKDAYS.INTL's arguments is not a valid date (if the date was entered as text for example)
  • #NUM! : occurs If the weekend argument is not one of the designated choices
  • #NUM!: occurs if the Start_date and End_date arguments are outside Excel's range of acceptable dates
  • If the End_date occurs before the Start_date the number of workdays in the answer cell will be a negative number

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