ISOWEEKNUM
Returns the ISO week number for a given date.
Syntax 🔗
=ISOWEEKNUM(date)
date | The date for which you want to determine the ISO week number. |
About ISOWEEKNUM 🔗
Use the ISOWEEKNUM function to find the week number for a given date based on the ISO 8601 standard. This is useful for organizing dates according to the standardized week numbering system, which is commonly used in business and international contexts. The ISO system numbers weeks from 1 to 53, with week 1 being the week containing the first Thursday of the year.
Examples 🔗
Suppose you have a date cell containing '05/15/2022'. To determine the ISO week number for this date, use the formula: =ISOWEEKNUM(A1). If A1 contains the date '05/15/2022', the ISOWEEKNUM function returns '19', indicating that '05/15/2022' falls in the 19th ISO week of the year.
Notes 🔗
1. The ISOWEEKNUM function follows the ISO 8601 standard, where the week containing January 4th is the first week of the year. Keep this in mind when using week numbers.2. Make sure the date input for the ISOWEEKNUM function is in a valid Excel date format or refer to a cell with a valid date for accurate results.
Questions 🔗
The ISO week numbering system aims to provide a standardized way of identifying weeks within a year, with week 1 defined as the week that contains the first Thursday of the year. This system helps facilitate international communication and consistent week-based calculations across different regions.
How does ISOWEEKNUM differ from the WEEKNUM function in Excel?While the WEEKNUM function in Excel calculates week numbers based on the user-defined start of the week, ISOWEEKNUM strictly adheres to the ISO 8601 standard for week numbering. ISOWEEKNUM ensures consistent week numbering across different geographies and cultures, making it ideal for international business and compliance purposes.
Can the ISOWEEKNUM function return a week number greater than 52?Yes, the ISO week numbering system used by ISOWEEKNUM allows for week numbers to reach up to 53 in a year, ensuring alignment with the standard's definition of weeks. This flexibility accommodates cases where the first day of the year falls on a Thursday or a leap year scenario.
Is the ISO week number output by ISOWEEKNUM dependent on the regional settings of Excel?No, the ISO week number returned by the ISOWEEKNUM function is not affected by the regional settings in Excel. It strictly follows the ISO 8601 standard for week numbering, ensuring consistent results regardless of the user's location settings.