Adding Django form widgets

I'm new to django and am working with the Calendarium package, i needed to edit it most places to make it fit my need and this is the last problem i cant get round. I have never seen anything like the way this package is set up and cant figure it out i have tried many ways to try to get these widgets working but none have worked so far

i tried:

lass EventMixin(object):
    """Mixin to handle event-related functions."""
    model = Event
    fields = '__all__'



    @method_decorator(permission_required('calendarium.add_event'))
    def dispatch(self, request, *args, **kwargs):
        retu super(EventMixin, self).dispatch(request, *args, **kwargs)


class EventUpdateView(EventMixin, UpdateView):
    """View to update information of an event."""
    pass


class EventCreateView(EventMixin, CreateView):
    model = Event
    form_class =  modelform_factory(Event,
    widgets={"start": AdminDateWidget })
    template_name = 'event_update.html'
    success_url = '/'

this among others, I don't know how far i should go in terms of adding code to this post, if you need any please ask. I would love to get this sorted ASAP