...
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:local="urn:local" extension-element-prefixes="msxsl">
<msxsl:script language="CSharp" implements-prefix="local">
public string dateTimeNow()
{
return DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ssZ");
}
</msxsl:script>
...
<xsl:value-of select="local:dateTimeNow()"/>