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

Data Analysis

  • How to count table rows in Excel
  • Conditional Formatting Rules in Excel
  • Create Scatter Chart in Excel
  • Number and Text Filters Examples in Excel
  • Conditional Formatting Color Scales Examples in Excel

References

  • How to get last row in mixed data with blanks in Excel
  • Find Closest Match in Excel Using INDEX, MATCH, ABS and MIN functions
  • Extract all partial matches in Excel
  • Multi-criteria lookup and transpose in Excel
  • Left Lookup in Excel

Data Validations

  • Excel Data validation date in next 30 days
  • Excel Data validation only dates between
  • Excel Data validation must begin with
  • Excel Data validation with conditional list
  • How To Create Drop-down List in Excel

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Your email address will not be published.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

  • OR function Examples in Excel
  • How to use IFS function in Excel
  • Extract multiple matches into separate rows in Excel
  • AND function: Description, Usage, Syntax, Examples and Explanation
  • SWITCH function example in Excel

Date Time

  • Count holidays between two dates in Excel
  • Convert Excel time to decimal seconds
  • Convert text timestamp into time in Excel
  • Add workdays no weekends in Excel
  • Add business days to date in Excel

Grouping

  • Group times into unequal buckets in Excel
  • Running count group by n size in Excel
  • Group numbers with VLOOKUP in Excel
  • Group numbers at uneven intervals in Excel
  • Group arbitrary text values in Excel

General

  • 3D SUMIF for multiple worksheets in Excel
  • How to choose page/paper size in Excel before Printing
  • How to calculate percentage of total in Excel
  • Excel Ribbon Quick Overview For Beginners
  • How to count total columns in range in Excel
© 2025 xlsoffice . All Right Reserved. | Teal Smiles | Abbreviations And Their Meaning