Turn tzdata install requirement into optional timezone dependency

.github/workflows/ci.yml

@@ -139,7 +139,7 @@ jobs:
     - name: install deps
       run: |
         pdm venv create --with-pip --force $PYTHON
-        pdm install -G testing -G email
+        pdm install -G testing -G email -G timezone
 
     - run: pdm info && pdm list
 
@@ -156,7 +156,7 @@ jobs:
         CONTEXT: ${{ runner.os }}-py${{ matrix.python-version }}-without-deps
 
     - name: install extra deps
-      run: pdm install -G testing-extra -G email
+      run: pdm install -G testing-extra -G email -G timezone
 
     - name: test with deps
       run: make test

.hyperlint/styles/config/vocabularies/hyperlint/accept.txt

@@ -6,6 +6,7 @@ Hyperlint
 preprocess
 tokenization
 tokenizer
+tzdata
 API
 APIs
 SDKs

docs/install.md

@@ -23,22 +23,26 @@ conda install pydantic -c conda-forge
 
 Pydantic has the following optional dependencies:
 
-* Email validation provided by the [email-validator](https://pypi.org/project/email-validator/) package.
+* `email`: Email validation provided by the [email-validator](https://pypi.org/project/email-validator/) package.
+* `timezone`: Fallback IANA time zone database provided by the [tzdata](https://pypi.org/project/tzdata/) package.
 
 To install optional dependencies along with Pydantic:
 
 ```bash
+# with the `email` extra:
 pip install pydantic[email]
+# or with `email` and `timezone` extras:
+pip install pydantic[email,timezone]
 ```
 
-Of course, you can also install requirements manually with `pip install email-validator`.
+Of course, you can also install requirements manually with `pip install email-validator tzdata`.
 
 ## Install from repository
 
 And if you prefer to install Pydantic directly from the repository:
 
 ```bash
 pip install git+https://github.com/pydantic/pydantic@main#egg=pydantic
-# or with the `email` extra:
-pip install git+https://github.com/pydantic/pydantic@main#egg=pydantic[email]
+# or with `email` and `timezone` extras:
+pip install git+https://github.com/pydantic/pydantic@main#egg=pydantic[email,timezone]
 ```

pyproject.toml

@@ -51,13 +51,15 @@ dependencies = [
     'typing-extensions>=4.12.2; python_version >= "3.13"',
     'annotated-types>=0.6.0',
     "pydantic-core==2.23.2",
-    # See: https://docs.python.org/3/library/zoneinfo.html#data-sources
-    'tzdata; python_version >= "3.9"',
 ]
 dynamic = ['version', 'readme']
 
 [project.optional-dependencies]
 email = ['email-validator>=2.0.0']
+timezone = [
+    # See: https://docs.python.org/3/library/zoneinfo.html#data-sources
+    'tzdata; python_version >= "3.9" and sys_platform == "win32"',
+]
 
 [project.urls]
 Homepage = 'https://github.com/pydantic/pydantic'