Can pandas.DatetimeIndex remember whether it is closed?

I have a pandas.DatetimeIndex for an interval ['2018-01-01', '2018-01-04') (start included, end excluded) and freq=1D:

>>> index = pd.DatetimeIndex(start='2018-01-01',
                             end='2018-01-04',
                             freq='1D',
                             closed='left')
DatetimeIndex(['2018-01-01', '2018-01-02', '2018-01-03'],
              dtype='datetime64[ns]',
              freq='D')

How can I obtain the correct open end='2018-01-04' attribute again? I need it for a DB query with timestamp ranges.

1. There is no index.end
2. index[-1] returns '2018-01-03'
3. index[-1] + index.freq works in this case but is wrong for freq='2D'

from Can pandas.DatetimeIndex remember whether it is closed?