[Answered ]-Mouse Over in a django template

There is no string formatting in django templates as there is in python. There is also a template tag which is able to retrieve todays date (https://docs.djangoproject.com/en/dev/ref/templates/builtins/#now). Hope this leads into the right direction.

You could try something like this:

<span class="green_box" onmouseover="I am Green and today is {% now "d-n-Y" %}">