Skip to content
Free Excel Tutorials
  • Home
  • Excel For Beginners
  • Excel Intermediate
  • Advanced Excel For Experts

Data Analysis

  • How To Filter Data in Excel
  • Everything about Charts in Excel
  • How to calculate average last N values in a table in Excel
  • How To Perform and Interpret Regression Analysis in Excel
  • Add Outline to Data in Excel

References

  • Vlookup Examples in Excel
  • How to use Excel INDIRECT Function
  • Lookup entire row in Excel
  • How to use Excel LOOKUP Function
  • Extract data with helper column in Excel

Data Validations

  • Excel Data validation number multiple 100
  • Excel Data validation whole percentage only
  • Excel Data validation don’t exceed total
  • Excel Data validation must contain specific text
  • Excel Data validation date in specific year

ISOWEEKNUM function: Description, Usage, Syntax, Examples and Explanation

by

What is ISOWEEKNUM function in Excel?

ISOWEEKNUM function is one of Date and Time functions in Microsoft Excel that returns number of the ISO week number of the year for a given date.

Syntax of ISOWEEKNUM function

ISOWEEKNUM(date)

The ISOWEEKNUM function syntax has the following arguments.

  • Date: Date is the date-time code used by Excel for date and time calculation.

ISOWEEKNUM formula explanation

  • Microsoft Excel stores dates as sequential numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
  • If the date argument is not a valid number, ISOWEEKNUM returns the #NUM! error value.
  • If the date argument is not a valid date type, ISOWEEKNUM returns the #VALUE! error value.

Example of ISOWEEKNUM function

Steps to follow:

1. Open a new Excel worksheet.

2. Copy data in the following table below and paste it in cell A1

Note: For formulas to show results, select them, press F2 key on your keyboard and then press Enter.

You can adjust the column widths to see all the data, if need be.

Date
3/9/2012
Formula Description Result
=ISOWEEKNUM(A2) Number of the week in the year that 3/9/2012 occurs, based on weeks beginning on the default, Monday (10). 10

Post navigation

Previous Post:

How to generate random date between two dates in Excel

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Learn Basic Excel

Ribbon
Workbook
Worksheets
Format Cells
Find & Select
Sort & Filter
Templates
Print
Share
Protect
Keyboard Shortcuts

Categories

  • Charts
  • Data Analysis
  • Data Validation
  • Excel Functions
    • Cube Functions
    • Database Functions
    • Date and Time Functions
    • Engineering Functions
    • Financial Functions
    • Information Functions
    • Logical Functions
    • Lookup and Reference Functions
    • Math and Trig Functions
    • Statistical Functions
    • Text Functions
    • Web Functions
  • Excel VBA
  • Excel Video Tutorials
  • Formatting
  • Grouping
  • Others

Logical Functions

  • Excel If, Nested If, And/Or Criteria Examples
  • Nested IF function example in Excel
  • IF, AND, OR and NOT Functions Examples in Excel
  • Complete List of Excel Logical Functions, References and Examples
  • SWITCH function: Description, Usage, Syntax, Examples and Explanation

Date Time

  • Custom weekday abbreviation in Excel
  • Get days between dates ignoring years in Excel
  • ISOWEEKNUM function: Description, Usage, Syntax, Examples and Explanation
  • How to get number of days, weeks, months or years between two dates in Excel
  • Get age from birthday in Excel

Grouping

  • If cell contains one of many things in Excel
  • Running count group by n size in Excel
  • Categorize text with keywords in Excel
  • Group times into unequal buckets in Excel
  • Calculate conditional mode with criteria in Excel

General

  • How to Delete Cells, Row and Rows in Excel
  • How to calculate percent variance in Excel
  • Advanced Number Formats in Excel
  • How to increase by percentage in Excel
  • How to calculate profit margin percentage in Excel
© 2025 xlsoffice . All Right Reserved. | Teal Smiles | Abbreviations And Their Meaning