From 8f251e85eee926c2e89c9fe2802f382fe62129c2 Mon Sep 17 00:00:00 2001
From: Om Singhal <wengsinghal@gmail.com>
Date: Fri, 11 Sep 2026 01:49:03 -0400
Subject: [PATCH] [DevTest Labs] `az lab vm create`: Fix `--expiration-date`
 always failing with a datetime comparison error

AAZDateTimeArg normalizes --expiration-date into an offset aware UTC
timestamp before pre_operations runs, so _validate_expiration_date
always parsed an offset aware datetime. It compared that against the
naive datetime.datetime.utcnow(), which raises TypeError for every
value, making the argument unusable.

Compare against datetime.datetime.now(datetime.timezone.utc) instead.
That also drops a utcnow() call deprecated since Python 3.12.

Fixes #31611
---
 .../lab/tests/latest/test_lab_validators.py   | 34 ++++++++++++++++++-
 .../cli/command_modules/lab/validators.py     |  5 ++-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/azure-cli/azure/cli/command_modules/lab/tests/latest/test_lab_validators.py b/src/azure-cli/azure/cli/command_modules/lab/tests/latest/test_lab_validators.py
index b624a177420..1e8a489a716 100644
--- a/src/azure-cli/azure/cli/command_modules/lab/tests/latest/test_lab_validators.py
+++ b/src/azure-cli/azure/cli/command_modules/lab/tests/latest/test_lab_validators.py
@@ -3,10 +3,14 @@
 # Licensed under the MIT License. See License.txt in the project root for license information.
 # --------------------------------------------------------------------------------------------
 
+import datetime
 import unittest
 from azure.mgmt.core.tools import is_valid_resource_id
+from azure.cli.core.aaz import AAZArgumentsSchema, AAZDateTimeArg
+from azure.cli.core.aaz._command_ctx import AAZCommandCtx
 from azure.cli.core.azclierror import ArgumentUsageError
-from azure.cli.command_modules.lab.validators import _update_artifacts
+from azure.cli.core.mock import DummyCli
+from azure.cli.command_modules.lab.validators import _update_artifacts, _validate_expiration_date
 
 
 class ValidatorsCommandTest(unittest.TestCase):
@@ -65,3 +69,31 @@ def test_update_artifacts(self):
         del invalid_artifact['artifact_id']
         with self.assertRaises(ArgumentUsageError):
             _update_artifacts([invalid_artifact], self.lab_resource_id)
+
+
+class ExpirationDateValidatorTest(unittest.TestCase):
+    @staticmethod
+    def _build_args(expiration_date=None):
+        """ Builds the args `az lab vm create` hands to the validator. """
+        schema = AAZArgumentsSchema()
+        schema.expiration_date = AAZDateTimeArg(options=['--expiration-date'])
+        command_args = {} if expiration_date is None else {'expiration_date': expiration_date}
+        ctx = AAZCommandCtx(cli_ctx=DummyCli(), schema=schema, command_args=command_args)
+        ctx.format_args()
+        return ctx.args
+
+    def test_expiration_date_in_future(self):
+        future = datetime.datetime.now(datetime.timezone.utc) + datetime.timedelta(days=2)
+        # No offset, a Z suffix and an explicit offset all reach the validator as UTC timestamps.
+        for expiration_date in (future.strftime('%Y-%m-%d %H:%M:%S'),
+                                future.strftime('%Y-%m-%dT%H:%M:%S.%fZ'),
+                                future.strftime('%Y-%m-%d %H:%M:%S+00:00')):
+            _validate_expiration_date(self._build_args(expiration_date))
+
+    def test_expiration_date_in_past(self):
+        past = datetime.datetime.now(datetime.timezone.utc) - datetime.timedelta(days=2)
+        with self.assertRaises(ArgumentUsageError):
+            _validate_expiration_date(self._build_args(past.strftime('%Y-%m-%dT%H:%M:%S.%fZ')))
+
+    def test_expiration_date_not_provided(self):
+        _validate_expiration_date(self._build_args())
diff --git a/src/azure-cli/azure/cli/command_modules/lab/validators.py b/src/azure-cli/azure/cli/command_modules/lab/validators.py
index 6cf9bcbc450..d7e858b50e4 100644
--- a/src/azure-cli/azure/cli/command_modules/lab/validators.py
+++ b/src/azure-cli/azure/cli/command_modules/lab/validators.py
@@ -115,7 +115,10 @@ def _validate_expiration_date(args):
     if has_value(args.expiration_date):
         import datetime
         import dateutil.parser
-        if datetime.datetime.utcnow() >= dateutil.parser.parse(args.expiration_date.to_serialized_data()):
+        # AAZDateTimeArg normalizes --expiration-date into an offset-aware UTC timestamp, so "now"
+        # has to be offset-aware too. datetime.utcnow() is naive and the comparison raises TypeError.
+        if datetime.datetime.now(datetime.timezone.utc) >= \
+                dateutil.parser.parse(args.expiration_date.to_serialized_data()):
             raise ArgumentUsageError(
                 "Expiration date '{}' must be in future.".format(args.expiration_date.to_serialized_data()))