Pandas version checks

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  • [x] I have confirmed this bug exists on the latest version of pandas.

  • [ ] I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

import pandas as pd
test = pd.Series([pd.date_range("2020-01-01T00:00:00Z", "2020-01-01T02:00:00Z", freq="1h", unit="ms")])
test.explode().dtype

Issue Description

The docs for pd.date_range state that the unit keyword argument is the resolution of timestamps in the returned DatetimeIndex, which is true---and counter to the usage of unit elsewhere, e.g. in pd.to_datetime. Regardless of this discrepancy, explode does not respect the millisecond resolution of timestamps in a DatetimeIndex, converting them to nanosecond resolution in the returned Series or DataFrame.

Expected Behavior

dtypes should not be changed by explode.

Installed Versions

INSTALLED VERSIONS

commit : 2cc37625532045f4ac55b27176454bbbc9baf213 python : 3.11.13 python-bits : 64 OS : Linux OS-release : 5.15.0-139-generic Version : #149~20.04.1-Ubuntu SMP Wed Apr 16 08:29:56 UTC 2025 machine : x86_64 processor : byteorder : little LC_ALL : None LANG : C.UTF-8 LOCALE : en_US.UTF-8

pandas : 2.3.0 numpy : 1.26.4 pytz : 2025.2 dateutil : 2.9.0.post0 pip : 25.1.1 Cython : None sphinx : 8.2.3 IPython : 9.3.0 adbc-driver-postgresql: None adbc-driver-sqlite : None bs4 : 4.13.4 blosc : None bottleneck : None dataframe-api-compat : None fastparquet : None fsspec : 2025.5.1 html5lib : None hypothesis : None gcsfs : None jinja2 : 3.1.6 lxml.etree : None matplotlib : 3.10.3 numba : None numexpr : None odfpy : None openpyxl : None pandas_gbq : None psycopg2 : None pymysql : None pyarrow : 20.0.0 pyreadstat : None pytest : 8.4.0 python-calamine : None pyxlsb : None s3fs : 2025.5.1 scipy : 1.15.3 sqlalchemy : 2.0.41 tables : None tabulate : None xarray : None xlrd : None xlsxwriter : None zstandard : None tzdata : 2025.2 qtpy : None pyqt5 : None

Comment From: Narendersingh007

Hello, I’m interested in contributing a fix for this issue.

Comment From: asishm

Thanks for the report. This seems to be fixed in main.