Find the ISO week number of a year for a given date.
The Excel ISOWEEKNUM function return ISO week number considering a week begins on Monday. Example; to find ISO week number for any date (09-03-2017), use = ISOWEEKNUM(date) that returns 10.
Under ISO week date system, the first week starts on Monday of the calendar year with a Thursday.
date – A valid argument of date or serial number recognized by Excel
An Integer between 1 and 52 or 53 representing week number of a specific date as per ISO standard.
- Excel ISOWEEKNUM function categorize dates by the week number of the year based on ISO date standards.
- Make sure to use the date as a cell reference rather than inputting it manually.
- Use the WEEKNUM function to returns the normal week number in the year.