@register.filter
def parse_isotime(timestr, default=None):
    try:
        return iso8601.parse_date(timestr)
    except (iso8601.ParseError, TypeError):
        return default or ''
This duplicates oslo timeutils parse_isotime but with a
dataset/ETHPy150Open Havate/havate-openstack/proto-build/gui/horizon/Horizon_GUI/horizon/utils/filters.py/parse_isotime