The Excel Isoweeknum function returns the ISO week number of a supplied date.
This function was introduced in Excel 2013 and so is not available in earlier versions of Excel.
The format of the Isoweeknum function is:
Note that Microsoft advises that you do not type dates directly into functions, as Excel may interpret text representations of dates differently, depending on the date interpretation settings on your computer. Therefore the date argument for the Isoweeknum function should be input as either:
Further information and examples of the Excel ISOWEEKNUM function are provided on the Microsoft Office website.
|#NUM!||-||Occurs if the supplied date argument is a numeric value, but is not a valid date.|
|#VALUE!||-||Occurs if the supplied date argument is a text value that can not be interpreted as a date.|