Dynamic text from a Javascript shortcode

Hello,
I’ve this js code in a shortcode made with Shortcoder (Create Shortcodes for Anything) plugin:

<script language=”Javascript”>
document.cookie = “myJavascriptVar = ”
today = new Date()
document.write(today.getFullYear(),today.getMonth(),today.getDate(),today.getHours(),today.getMinutes(),today.getSeconds());
</script>

Now in CF7 with the Dynamic Text Extension plugin I can assign by default a value in a field obtaiden from the shortcode but in this field appair the entire code and not the result of the js code.
Where is the problem?
Thank you