Activities --> Add Task --> Due Date --> make it mandatory

Hi  Forum

Is it possible without Jave code!! to make the Due date a mandatory field within the 'Add Task' dialogue below, this is  different for to the 'Task' entity form used elsewhere in CRM, this is specific to within opportunities within the post/Activities section which  I assume this is out of the box CRM functionality??  I cannot find the form to make the due date mandatory.. please check out the screenshot below.

Any help would be appreciated...

many thanks

stu