def _get_formatted_date_link(base_link, end_date, num_days):
    return '<li><a href="%s?startdate=%s&enddate=%s">%s</a></li>' % (base_link, 
                                                                (timedelta(days=num_days) - end_date).strftime('%m/%d/%Y'), 
                                                                end_date.strftime('%m/%d/%Y'), 
                                                                _get_time_interval_display(num_days))
dataset/ETHPy150Open dimagi/commcare-hq/corehq/apps/hqwebapp/templatetags/mainreport_tags.py/_get_formatted_date_link/swapped operands of `-`