python-openxml
diff --git a/‎features/steps/coreprops.py
Lines changed: 9 additions & 9 deletions b/‎features/steps/coreprops.py
Lines changed: 9 additions & 9 deletions
diff --git a/‎pyproject.toml
Lines changed: 11 additions & 0 deletions b/‎pyproject.toml
Lines changed: 11 additions & 0 deletions
diff --git a/‎pyrightconfig.json
Lines changed: 0 additions & 21 deletions b/‎pyrightconfig.json
Lines changed: 0 additions & 21 deletions
diff --git a/‎src/docx/opc/parts/coreprops.py
Lines changed: 1 addition & 1 deletion b/‎src/docx/opc/parts/coreprops.py
Lines changed: 1 addition & 1 deletion
diff --git a/‎src/docx/oxml/coreprops.py
Lines changed: 2 additions & 2 deletions b/‎src/docx/oxml/coreprops.py
Lines changed: 2 additions & 2 deletions
diff --git a/‎tests/opc/parts/test_coreprops.py
Lines changed: 6 additions & 3 deletions b/‎tests/opc/parts/test_coreprops.py
Lines changed: 6 additions & 3 deletions
diff --git a/‎tests/opc/test_coreprops.py
Lines changed: 2 additions & 2 deletions b/‎tests/opc/test_coreprops.py
Lines changed: 2 additions & 2 deletions
diff --git a/‎tox.ini
Lines changed: 1 addition & 1 deletion b/‎tox.ini
Lines changed: 1 addition & 1 deletion
@@ -1,6 +1,6 @@
 """Gherkin step implementations for core properties-related features."""
 
-from datetime import datetime, timedelta
+import datetime as dt
 
 from behave import given, then, when
 from behave.runner import Context
@@ -38,13 +38,13 @@ def when_I_assign_new_values_to_the_properties(context: Context):
         ("category", "Category"),
         ("comments", "Description"),
         ("content_status", "Content Status"),
-        ("created", datetime(2013, 6, 15, 12, 34, 56)),
+        ("created", dt.datetime(2013, 6, 15, 12, 34, 56, tzinfo=dt.timezone.utc)),
         ("identifier", "Identifier"),
         ("keywords", "key; word; keyword"),
         ("language", "Language"),
         ("last_modified_by", "Last Modified By"),
-        ("last_printed", datetime(2013, 6, 15, 12, 34, 56)),
-        ("modified", datetime(2013, 6, 15, 12, 34, 56)),
+        ("last_printed", dt.datetime(2013, 6, 15, 12, 34, 56, tzinfo=dt.timezone.utc)),
+        ("modified", dt.datetime(2013, 6, 15, 12, 34, 56, tzinfo=dt.timezone.utc)),
         ("revision", 9),
         ("subject", "Subject"),
         ("title", "Title"),
@@ -66,8 +66,8 @@ def then_a_core_properties_part_with_default_values_is_added(context: Context):
     assert core_properties.revision == 1
     # core_properties.modified only stores time with seconds resolution, so
     # comparison needs to be a little loose (within two seconds)
-    modified_timedelta = datetime.utcnow() - core_properties.modified
-    max_expected_timedelta = timedelta(seconds=2)
+    modified_timedelta = dt.datetime.now(dt.timezone.utc) - core_properties.modified
+    max_expected_timedelta = dt.timedelta(seconds=2)
     assert modified_timedelta < max_expected_timedelta
 
 
@@ -85,13 +85,13 @@ def then_the_core_property_values_match_the_known_values(context: Context):
         ("category", "Category"),
         ("comments", "Description"),
         ("content_status", "Content Status"),
-        ("created", datetime(2014, 12, 13, 22, 2, 0)),
+        ("created", dt.datetime(2014, 12, 13, 22, 2, 0, tzinfo=dt.timezone.utc)),
         ("identifier", "Identifier"),
         ("keywords", "key; word; keyword"),
         ("language", "Language"),
         ("last_modified_by", "Steve Canny"),
-        ("last_printed", datetime(2014, 12, 13, 22, 2, 42)),
-        ("modified", datetime(2014, 12, 13, 22, 6, 0)),
+        ("last_printed", dt.datetime(2014, 12, 13, 22, 2, 42, tzinfo=dt.timezone.utc)),
+        ("modified", dt.datetime(2014, 12, 13, 22, 6, 0, tzinfo=dt.timezone.utc)),
         ("revision", 2),
         ("subject", "Subject"),
         ("title", "Title"),
 
@@ -42,6 +42,17 @@ Repository = "https://github.com/python-openxml/python-docx"
 line-length = 100
 target-version = ["py37", "py38", "py39", "py310", "py311"]
 
+[tool.pyright]
+include = ["src/docx", "tests"]
+pythonPlatform = "All"
+pythonVersion = "3.8"
+reportImportCycles = true
+reportUnnecessaryCast = true
+reportUnnecessaryTypeIgnoreComment = true
+stubPath = "./typings"
+typeCheckingMode = "strict"
+verboseOutput = true
+
 [tool.pytest.ini_options]
 filterwarnings = [
     # -- exit on any warning not explicitly ignored here --
 
@@ -31,7 +31,7 @@ def default(cls, package: OpcPackage):
         core_properties.title = "Word Document"
         core_properties.last_modified_by = "python-docx"
         core_properties.revision = 1
-        core_properties.modified = dt.datetime.utcnow()
+        core_properties.modified = dt.datetime.now(dt.timezone.utc)
         return core_properties_part
 
     @property
 
@@ -254,8 +254,8 @@ def _parse_W3CDTF_to_datetime(cls, w3cdtf_str: str) -> dt.datetime:
             tmpl = "could not parse W3CDTF datetime string '%s'"
             raise ValueError(tmpl % w3cdtf_str)
         if len(offset_str) == 6:
-            return cls._offset_dt(dt_, offset_str)
-        return dt_
+            dt_ = cls._offset_dt(dt_, offset_str)
+        return dt_.replace(tzinfo=dt.timezone.utc)
 
     def _set_element_datetime(self, prop_name: str, value: dt.datetime):
         """Set date/time value of child element having `prop_name` to `value`."""
 
@@ -1,6 +1,8 @@
 """Unit test suite for the docx.opc.parts.coreprops module."""
 
-from datetime import datetime, timedelta
+from __future__ import annotations
+
+import datetime as dt
 
 import pytest
 
@@ -35,8 +37,9 @@ def it_can_create_a_default_core_properties_part(self, package_: Mock):
         assert core_properties.title == "Word Document"
         assert core_properties.last_modified_by == "python-docx"
         assert core_properties.revision == 1
-        delta = datetime.utcnow() - core_properties.modified
-        max_expected_delta = timedelta(seconds=2)
+        assert core_properties.modified is not None
+        delta = dt.datetime.now(dt.timezone.utc) - core_properties.modified
+        max_expected_delta = dt.timedelta(seconds=2)
         assert delta < max_expected_delta
 
     # fixtures ---------------------------------------------
 
@@ -68,8 +68,8 @@ def it_can_change_the_string_property_values(self, prop_name: str, tagname: str,
     @pytest.mark.parametrize(
         ("prop_name", "expected_datetime"),
         [
-            ("created", dt.datetime(2012, 11, 17, 16, 37, 40)),
-            ("last_printed", dt.datetime(2014, 6, 4, 4, 28)),
+            ("created", dt.datetime(2012, 11, 17, 16, 37, 40, tzinfo=dt.timezone.utc)),
+            ("last_printed", dt.datetime(2014, 6, 4, 4, 28, tzinfo=dt.timezone.utc)),
             ("modified", None),
         ],
     )
 
@@ -1,5 +1,5 @@
 [tox]
-envlist = py38, py39, py310, py311
+envlist = py38, py39, py310, py311, py312
 
 [testenv]
 deps = -rrequirements-test.txt