# ISOWEEKNUM Function

The ISOWEEKNUM function is one of the date and time functions. It used to return number of the ISO week number of the year for a given date. Returns a number between 1 and 54.

The ISOWEEKNUM function syntax is:

ISOWEEKNUM(date)

where

date is a date you want to find the ISO week number of. Can be a reference to a cell containing a date or a date returned by the Date function or other date and time function.

To apply the ISOWEEKNUM function,

1. select the cell where you wish to display the result,
2. click the Insert function icon situated at the top toolbar,
   or right-click within a selected cell and select the Insert Function option from the menu,
   or click the icon situated at the formula bar,
3. select the Date and time function group from the list,
4. click the ISOWEEKNUM function,
5. enter the required argument,
6. press the Enter button.

The result will be displayed in the selected cell.