def METHOD_NAME(request, year, number):
    calendar = get_object_or_404(AdventCalendar, year=year)
    door = get_object_or_404(AdventDoor, calendar=calendar, number=number)
    my_next = request.GET.get("next")
    if door.is_today:
        door.winner = None
        door.save()
    return redirect(my_next)