diff --git a/presubmit_canned_checks.py b/presubmit_canned_checks.py
index 1edc2ac70..b0d13c730 100644
--- a/presubmit_canned_checks.py
+++ b/presubmit_canned_checks.py
@@ -8,7 +8,6 @@ import functools
 import io as _io
 import os as _os
 import time
-import zoneinfo
 
 import metadata.discover
 import metadata.validate
@@ -907,7 +906,7 @@ def CheckChromiumDependencyMetadata(input_api, output_api, file_filter=None):
 
 _IGNORE_FREEZE_FOOTER = 'Ignore-Freeze'
 
-_FREEZE_TZ = zoneinfo.ZoneInfo("America/Los_Angeles")
+_FREEZE_TZ = datetime.timezone(-datetime.timedelta(hours=8), 'PST')
 _FREEZE_START = datetime.datetime(2023, 12, 15, 0, 0, tzinfo=_FREEZE_TZ)
 _FREEZE_END = datetime.datetime(2024, 1, 2, 0, 0, tzinfo=_FREEZE_TZ)
 
diff --git a/tests/.vpython3 b/tests/.vpython3
new file mode 100644
index 000000000..305788e28
--- /dev/null
+++ b/tests/.vpython3
@@ -0,0 +1,104 @@
+# TODO - crbug/346784198: Delete this file once the entire infra is on 3.11 so
+# that the vpython spec under the root directory will be used.
+
+python_version: "3.8"
+# The default set of platforms vpython checks for does not yet include mac-arm64.
+# Setting `verify_pep425_tag` to the list of platforms we explicitly must support
+# allows us to ensure that vpython specs stay mac-arm64-friendly
+verify_pep425_tag: [
+    {python: "cp38", abi: "cp38", platform: "manylinux1_x86_64"},
+    {python: "cp38", abi: "cp38", platform: "linux_arm64"},
+    {python: "cp38", abi: "cp38", platform: "macosx_10_10_intel"},
+    {python: "cp38", abi: "cp38", platform: "macosx_11_0_arm64"},
+    {python: "cp38", abi: "cp38", platform: "win32"},
+    {python: "cp38", abi: "cp38", platform: "win_amd64"}
+]
+
+# Used by:
+#   auth.py
+#   gerrit_util.py
+#   git_cl.py
+#   my_activity.py
+#   TODO(crbug.com/1002153): Add ninjalog_uploader.py
+wheel: <
+  name: "infra/python/wheels/httplib2-py3"
+  version: "version:0.13.1"
+>
+wheel: <
+  name: "infra/python/wheels/six-py2_py3"
+  version: "version:1.10.0"
+>
+
+# Used by:
+#    presubmit_support.py
+wheel: <
+  name: "infra/python/wheels/requests-py3"
+  version: "version:2.31.0"
+>
+wheel: <
+  name: "infra/python/wheels/charset_normalizer-py3"
+  version: "version:2.0.4"
+>
+wheel: <
+  name: "infra/python/wheels/urllib3-py2_py3"
+  version: "version:1.26.6"
+>
+wheel: <
+  name: "infra/python/wheels/idna-py2_py3"
+  version: "version:2.8"
+>
+wheel: <
+  name: "infra/python/wheels/brotli/${vpython_platform}"
+  version: "version:1.0.9"
+>
+
+# Used by:
+#    presubmit_canned_checks.py (via zoneinfo)
+wheel: <
+  name: "infra/python/wheels/tzdata-py2_py3"
+  version: "version:2023.4"
+>
+
+# Used by:
+#   my_activity.py
+wheel: <
+  name: "infra/python/wheels/python-dateutil-py2_py3"
+  version: "version:2.7.3"
+>
+
+# May be required to talk to 3P servers.
+# Fixes https://crbug.com/1255921
+wheel: <
+  name: "infra/python/wheels/certifi-py2_py3"
+  version: "version:2021.5.30"
+>
+
+# Used by:
+#   autoninja.py
+wheel: <
+  name: "infra/python/wheels/google-auth-py3"
+  version: "version:2.16.2"
+>
+wheel: <
+  name: "infra/python/wheels/cachetools-py3"
+  version: "version:4.2.2"
+>
+wheel: <
+  name: "infra/python/wheels/pyasn1_modules-py2_py3"
+  version: "version:0.2.8"
+>
+wheel: <
+  name: "infra/python/wheels/rsa-py3"
+  version: "version:4.7.2"
+>
+wheel: <
+  name: "infra/python/wheels/pyasn1-py2_py3"
+  version: "version:0.4.8"
+>
+
+# Used by:
+#   tests/autoninja_test.py
+wheel: <
+  name: "infra/python/wheels/parameterized-py2_py3"
+  version: "version:0.8.1"
+>
diff --git a/tests/gclient_eval_unittest.py b/tests/gclient_eval_unittest.py
index 647ec1a43..03decdf30 100755
--- a/tests/gclient_eval_unittest.py
+++ b/tests/gclient_eval_unittest.py
@@ -93,8 +93,8 @@ class GClientEvalTest(unittest.TestCase):
     def test_not_whitelisted(self):
         with self.assertRaises(ValueError) as cm:
             gclient_eval._gclient_eval('[x for x in [1, 2, 3]]')
-        self.assertIn('unexpected AST node: <ast.ListComp object',
-                      str(cm.exception))
+        self.assertIn('unexpected AST node', str(cm.exception))
+        self.assertIn('ast.ListComp object', str(cm.exception))
 
     def test_dict_ordered(self):
         for test_case in itertools.permutations(range(4)):
diff --git a/tests/presubmit_diff_test.py b/tests/presubmit_diff_test.py
index 0c2c14c4b..c63fdc790 100755
--- a/tests/presubmit_diff_test.py
+++ b/tests/presubmit_diff_test.py
@@ -8,6 +8,7 @@ import os
 import sys
 import tempfile
 import unittest
+from typing import Dict, List
 from unittest import mock
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
@@ -51,7 +52,7 @@ class PresubmitDiffTest(unittest.TestCase):
     def tearDown(self):
         gclient_utils.rmtree(self.root)
 
-    def _test_create_diffs(self, files: list[str], expected: dict[str, str]):
+    def _test_create_diffs(self, files: List[str], expected: Dict[str, str]):
         actual = presubmit_diff.create_diffs("host", "repo", "ref", self.root,
                                              files)
         self.assertEqual(actual.keys(), expected.keys())