DEPS/TST: tzdata is optional, not required

ci/deps/actions-310.yaml

@@ -47,6 +47,7 @@ dependencies:
   - scipy
   - sqlalchemy
   - tabulate
+  - tzdata>=2022.1
   - xarray
   - xlrd
   - xlsxwriter

ci/deps/actions-38-minimum_versions.yaml

@@ -49,6 +49,7 @@ dependencies:
   - scipy=1.7.1
   - sqlalchemy=1.4.16
   - tabulate=0.8.9
+  - tzdata=2022.1
   - xarray=0.19.0
   - xlrd=2.0.1
   - xlsxwriter=1.4.3

ci/deps/actions-39.yaml

@@ -47,6 +47,7 @@ dependencies:
   - scipy
   - sqlalchemy
   - tabulate
+  - tzdata>=2022.1
   - xarray
   - xlrd
   - xlsxwriter

doc/source/getting_started/install.rst

@@ -270,6 +270,15 @@ For example, :func:`pandas.read_hdf` requires the ``pytables`` package, while
 optional dependency is not installed, pandas will raise an ``ImportError`` when
 the method requiring that dependency is called.
 
+Timezones
+^^^^^^^^^
+
+========================= ================== =============================================================
+Dependency                Minimum Version    Notes
+========================= ================== =============================================================
+tzdata                    2022.1             Allows the use of ``zoneinfo`` timezones with pandas
+========================= ================== =============================================================
+
 Visualization
 ^^^^^^^^^^^^^
 

environment.yml

@@ -48,6 +48,7 @@ dependencies:
   - scipy
   - sqlalchemy
   - tabulate
+  - tzdata>=2022.1
   - xarray
   - xlrd
   - xlsxwriter

pandas/_libs/tslibs/timezones.pyx

@@ -3,10 +3,13 @@ from datetime import (
     timezone,
 )
 
+from pandas.compat._optional import import_optional_dependency
+
 try:
     # py39+
     import zoneinfo
     from zoneinfo import ZoneInfo
+    import_optional_dependency("tzdata", errors="raise", min_version="2022.1")
 except ImportError:
     zoneinfo = None
     ZoneInfo = None

pandas/compat/_optional.py

@@ -44,6 +44,7 @@
     "xlwt": "1.3.0",
     "xlsxwriter": "1.4.3",
     "zstandard": "0.15.2",
+    "tzdata": "2022.1",
 }
 
 # A mapping from import name to package name (on PyPI) for packages where

pandas/conftest.py

@@ -79,6 +79,14 @@
     # Import "zoneinfo" could not be resolved (reportMissingImports)
     import zoneinfo  # type: ignore[no-redef]
 
+    # Although zoneinfo can be imported in Py39, it is effectively
+    # "not available" without tzdata/IANA tz data.
+    # We will set zoneinfo to not found in this case
+    try:
+        zoneinfo.ZoneInfo("UTC")
+    except zoneinfo.ZoneInfoNotFoundError:
+        zoneinfo = None
+
 # Until https://github.com/numpy/numpy/issues/19078 is sorted out, just suppress
 suppress_npdev_promotion_warning = pytest.mark.filterwarnings(
     "ignore:Promotion of numbers and bools:FutureWarning"

requirements-dev.txt

@@ -39,6 +39,7 @@ s3fs
 scipy
 sqlalchemy
 tabulate
+tzdata>=2022.1
 xarray
 xlrd
 xlsxwriter