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

Data Analysis

  • How To Perform and Interpret Regression Analysis in Excel
  • How to Create One and Two Variable Data Tables in Excel
  • How to Create Area Chart in Excel
  • How to Create Column Chart in Excel
  • Conflicting Multiple Conditional Formatting Rules in Excel

References

  • Two-column Lookup in Excel
  • Convert text string to valid reference in Excel using Indirect function
  • How to retrieve first match between two ranges in Excel
  • How to get relative column numbers in a range in Excel
  • INDEX function: Description, Usage, Syntax, Examples and Explanation

Data Validations

  • Excel Data validation date in next 30 days
  • Excel Data validation must contain specific text
  • Excel Data validation don’t exceed total
  • Excel Data validation number multiple 100
  • Excel Data validation allow weekday only

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

  • Invoice status with nested if in Excel
  • How to use Excel AND Function
  • IFERROR function: Description, Usage, Syntax, Examples and Explanation
  • IF with boolean logic in Excel
  • Excel If, Nested If, And/Or Criteria Examples

Date Time

  • How to calculate project start date based on end date in Excel
  • HOUR function: Description, Usage, Syntax, Examples and Explanation
  • Add workdays to date custom weekends in Excel
  • Count dates in current month in Excel
  • How to get Weekdays, Working days between Two Dates in Excel

Grouping

  • Calculate conditional mode with criteria in Excel
  • Group numbers at uneven intervals in Excel
  • If cell contains one of many things in Excel
  • Map text to numbers in Excel
  • Map inputs to arbitrary values in Excel

General

  • Sum by group in Excel
  • Cell References: Relative, Absolute and Mixed Referencing Examples
  • How to calculate project complete percentage in Excel
  • Transpose: Switch ‘Rows to Columns’ or ‘Columns to Rows’ in Excel
  • How to Create Calendar in Excel
© 2026 xlsoffice . All Right Reserved. | Teal Smiles | Abbreviations And Their Meaning