ISOWEEKNUM Function Explained

The ISOWEEKNUM Function in Microsoft Excel returns the ISO week number of a given date. It takes a single argument, which is a date, and returns a number between 1 and 53, representing the week of the year for the given date.

ISOWEEKNUM Function Syntax

ISOWEEKNUM(serial_number, [return_type])

  • serial_number: The date of the week you want to find the ISO week number for.
  • return_type: (Optional) A number that determines the type of ISO week number to return. The default is 1.