DEP: Remove tzdata as a hard dependency outside of Windows

Author: rhshadrach

README.md

@@ -115,7 +115,7 @@ details, see the commit logs at https://github.com/pandas-dev/pandas.
 ## Dependencies
 - [NumPy - Adds support for large, multi-dimensional arrays, matrices and high-level mathematical functions to operate on these arrays](https://www.numpy.org)
 - [python-dateutil - Provides powerful extensions to the standard datetime module](https://dateutil.readthedocs.io/en/stable/index.html)
-- [tzdata - Provides an IANA time zone database](https://tzdata.readthedocs.io/en/latest/)
+- [tzdata - Provides an IANA time zone database](https://tzdata.readthedocs.io/en/latest/) (Only required on Windows)
 
 See the [full installation instructions](https://pandas.pydata.org/pandas-docs/stable/install.html#dependencies) for minimum supported versions of required, recommended and optional dependencies.
 

doc/source/getting_started/install.rst

@@ -150,11 +150,13 @@ Package                                                          Minimum support
 ================================================================ ==========================
 `NumPy <https://numpy.org>`__                                    1.26.0
 `python-dateutil <https://dateutil.readthedocs.io/en/stable/>`__ 2.8.2
-`tzdata <https://pypi.org/project/tzdata/>`__                    2023.3
+*`tzdata <https://pypi.org/project/tzdata/>`__                    2023.3
 ================================================================ ==========================
 
 Generally, the minimum supported version is ~2 years old from the release date of a major or minor pandas version.
 
+* ``tzdata`` is only required on Windows.
+
 .. _install.optional_dependencies:
 
 Optional dependencies

doc/source/whatsnew/v3.0.0.rst

@@ -657,8 +657,6 @@ The following required dependencies were updated:
 +=================+======================+
 | numpy           | 1.26.0               |
 +-----------------+----------------------+
-| tzdata          | 2023.3               |
-+-----------------+----------------------+
 
 For `optional libraries <https://pandas.pydata.org/docs/getting_started/install.html>`_ the general recommendation is to use the latest version.
 The following table lists the lowest version per library that is currently being tested throughout the development of pandas.

pandas/_libs/tslibs/timezones.pyx

@@ -59,9 +59,6 @@ cdef bint is_utc_zoneinfo(tzinfo tz):
             utc_zoneinfo = zoneinfo.ZoneInfo("UTC")
         except zoneinfo.ZoneInfoNotFoundError:
             return False
-        # Warn if tzdata is too old, even if there is a system tzdata to alert
-        # users about the mismatch between local/system tzdata
-        import_optional_dependency("tzdata", errors="warn", min_version="2022.7")
 
     return tz is utc_zoneinfo
 

pyproject.toml

@@ -29,7 +29,7 @@ requires-python = '>=3.11'
 dependencies = [
   "numpy>=1.26.0",
   "python-dateutil>=2.8.2",
-  "tzdata>=2023.3"
+  "tzdata>=2023.3; platform_system == 'Windows'",
 ]
 classifiers = [
     'Development Status :: 5 - Production/Stable',