I'm trying to merge 2 tables with pandas.merge_asof. First table administrators_system_with_schemes_sort: salon_id staff_id date872646 2715596 2024-10-02 00:00:00872646 2715596 2024-10-03 00:00:00872646 2715596 2024-10-06 00:00:00872646 2715596 2024-10-07 00:00:00872646 2715596 2024-10-10 00:00:00872646 2715596 2024-10-11 00:00:00872646 2715596 2024-10-14 00:00:00872646 2715596 2024-10-15 00:00:00 Second table, bonus_and_penalty_for_staff_id_administrators_sort: salon_id staff_id date bonus penalty 872646 2715596 2024-10-12 00:00:00 4070 0 My code: astype_dict = { 'salon_id': 'int64', 'staff_id': 'int64' , 'date': 'datetime64[ns]' } administrators_system_with_schemes['date'] = [pd.to_datetime(date).date() for date in administrators_system_with_schemes['date']] bonus_and_penalty_for_staff_id_administrators['date'] = [pd.to_datetime(date).date() for date in bonus_and_penalty_for_staff_id_administrators['date']] administrators_system_with_schemes_sort = ( administrators_system_with_schemes.copy() .astype(astype_dict) .sort_values(by='date') ) bonus_and_penalty_for_staff_id_administrators_sort = ( bonus_and_penalty_for_staff_id_administrators.copy() .astype(astype_dict) .sort_values(by='date') ) administrators_system_with_schemes_with_additional_bonus_penalty = ( pd.merge_asof( left = administrators_system_with_schemes_sort , right = bonus_and_penalty_for_staff_id_administrators_sort , on = ['date'] , by = ['salon_id', 'staff_id'] , suffixes=['', '_y'] , direction='nearest' )) Result: | salon_id | staff_id | date | bonus | penalty | |-----------:|-----------:|:--------------------|--------:|----------:| | 872646 | 2715596 | 2024-10-02 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-03 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-06 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-07 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-10 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-11 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-14 00:00:00 | 0 | 0 | | 872646 | 2715596 | 2024-10-15 00:00:00 | 0 | 0 | Result is wrong, cause I got suitable value in tables. I've already tries many way to change data types, but still have this mistake. Any ideas, how to fix this problem? Thanks. Pandas ver. 2.1.4 (same error on ver.2.2.3). Python ver. 3.11.7 Continue reading...