# ISOWEEKNUM

## Content

This function calculates the number ISO week number of the year for the specified date.

## Syntax

`ISOWEEKNUM(date)`

## Arguments

[Required] The date to evaluate, specified as a serial number (e.g., 37806), a string (e.g., "5/9/2015"), or a cell reference.

## Examples

`ISOWEEKNUM("5/9/2015")` give the result 19.