Return tuple: [start, end] of np.datetime64 dates that are inclusive of the passed
    in datetimes.

def _start_end(date_range, dts):
    """
    Return tuple: [start, end] of np.datetime64 dates that are inclusive of the passed
    in datetimes.
    """
    # FIXME: timezones
    assert len(dts)
    _assert_no_timezone(date_range)
    date_range = to_pandas_closed_closed(date_range, add_tz=False)
    start = np.datetime64(date_range.start) if date_range.start else dts[0]
    end = np.datetime64(date_range.end) if date_range.end else dts[-1]
    return start, end