Here is my example:

import pandas as pd
import datetime
my_df = pd.DataFrame({'date_clmn': [datetime.date(2020, 1, 1),
                                    datetime.date(2020, 2, 1),
                                    datetime.date(2020, 3, 1)]})
my_df['lag_date'] = my_df.date_clmn - pd.DateOffset(months = 3)
my_df.lag_date.dt.date

The last line generates error:

AttributeError: Can only use .dt accessor with datetimelike values

As far as I understand dt accessor should work with timestamps. Why is it producing an error message?