localstack · bentsku · Dec 17, 2025 · Dec 17, 2025 · Dec 17, 2025 · Dec 17, 2025
@@ -1124,8 +1124,13 @@ def _parse_type_tag(self, stream: io.BufferedReader, additional_info: int):
             raise ProtocolParserError(f"Found CBOR tag not supported by botocore: {tag}")
 
     def _parse_type_datetime(self, value: int | float) -> datetime.datetime:
+        # CBOR overrides any timestamp format defined in the spec:
+        # https://smithy.io/2.0/additional-specs/protocols/smithy-rpc-v2.html#timestamp-type-serialization
+        # > This protocol uses epoch-seconds, also known as Unix timestamps, with millisecond (1/1000th of a second)
+        # > resolution. The timestampFormat MUST NOT be respected to customize timestamp serialization.
         if isinstance(value, (int, float)):
-            return self._convert_str_to_timestamp(str(value))
+            milli_precision_ts = int(value * 1000) / 1000
+            return datetime.datetime.fromtimestamp(milli_precision_ts, tz=datetime.UTC)
         else:
             raise ProtocolParserError(f"Unable to parse datetime value: {value}")
 

@@ -1372,43 +1372,5 @@
       "path": "/operations/CreateApiMapping/http/responseCode",
       "value": 200
     }
-  ],
-  "cloudwatch/2010-08-01/service-2": [
-    {
-      "op": "add",
-      "path": "/metadata/awsQueryCompatible",
-      "value": {}
-    },
-    {
-      "op": "add",
-      "path": "/metadata/jsonVersion",
-      "value": "1.0"
-    },
-    {
-      "op": "add",
-      "path": "/metadata/targetPrefix",
-      "value": "GraniteServiceVersion20100801"
-    },
-    {
-      "op": "replace",
-      "path": "/metadata/protocol",
-      "value": "smithy-rpc-v2-cbor"
-    },
-    {
-      "op": "replace",
-      "path": "/metadata/protocols",
-      "value": [
-        "smithy-rpc-v2-cbor",
-        "json",
-        "query"
-      ]
-    },
-    {
-      "op": "add",
-      "path": "/shapes/ConflictException/error",
-      "value": {
-        "httpStatusCode": 409
-      }
-    }
   ]
 }
diff --git a/localstack-core/localstack/services/cloudwatch/provider_v2.py b/localstack-core/localstack/services/cloudwatch/provider_v2.py
@@ -277,7 +277,7 @@ def get_metric_data(
             # Paginate
             timestamp_value_dicts = [
                 {
-                    "Timestamp": timestamp,
+                    "Timestamp": datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC),
                     "Value": float(value),
                 }
                 for timestamp, value in zip(timestamps, values, strict=False)

diff --git a/tests/aws/services/cloudwatch/test_cloudwatch.py b/tests/aws/services/cloudwatch/test_cloudwatch.py
@@ -1,6 +1,7 @@
 import gzip
 import json
 import logging
+import re
 import threading
 import time
 from datetime import UTC, datetime, timedelta, timezone
@@ -3026,6 +3027,36 @@ def _get_metric_data_sum():
         )
         snapshot.match("get-metric-data", response)
 
+        # we need special assertions for raw timestamp values, based on the protocol:
+        if protocol == "query":
+            timestamp = response["GetMetricDataResponse"]["GetMetricDataResult"][
+                "MetricDataResults"
+            ]["member"][0]["Timestamps"]["member"]
+            assert re.match(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z$", timestamp)
+
+        elif protocol == "json":
+            timestamp = response["MetricDataResults"][0]["Timestamps"][0]
+            assert isinstance(timestamp, float)
+            # assert this format: 1765977780.0
+            assert re.match(r"^\d{10}\.0", str(timestamp))
+        else:
+            timestamp = response["MetricDataResults"][0]["Timestamps"][0]
+            assert isinstance(timestamp, datetime)
+            assert timestamp.microsecond == 0
+            assert timestamp.year == now.year
+            assert now.day - 1 <= timestamp.day <= now.day + 1
+
+            # we need to decode more for CBOR, to verify we encode it the same way as AWS (datetime format + proper
+            # underlying format (float)
+            # See https://smithy.io/2.0/additional-specs/protocols/smithy-rpc-v2.html#timestamp-type-serialization
+            # https://datatracker.ietf.org/doc/html/rfc8949.html#section-3.4
+            response_raw = http_client.post_raw(
+                operation="GetMetricData",
+                payload=get_metric_input,
+            )
+            # assert that the timestamp is encoded as a Tag (6 major type) with Double of length 8
+            assert b"Timestamps\x9f\xc1\xfbA" in response_raw.content
+
     @markers.aws.validated
     @pytest.mark.skipif(is_old_provider(), reason="Wrong behavior in v1 in SetAlarmState")
     @pytest.mark.parametrize("protocol", ["json", "smithy-rpc-v2-cbor", "query"])

diff --git a/tests/aws/services/cloudwatch/test_cloudwatch.validation.json b/tests/aws/services/cloudwatch/test_cloudwatch.validation.json
@@ -1,29 +1,29 @@
 {
   "tests/aws/services/cloudwatch/test_cloudwatch.py::TestCloudWatchMultiProtocol::test_basic_operations_multiple_protocols[json]": {
-    "last_validated_date": "2025-10-06T14:45:54+00:00",
+    "last_validated_date": "2025-12-17T13:53:06+00:00",
     "durations_in_seconds": {
-      "setup": 0.82,
-      "call": 2.64,
-      "teardown": 0.01,
-      "total": 3.47
+      "setup": 0.56,
+      "call": 3.57,
+      "teardown": 0.0,
+      "total": 4.13
     }
   },
   "tests/aws/services/cloudwatch/test_cloudwatch.py::TestCloudWatchMultiProtocol::test_basic_operations_multiple_protocols[query]": {
-    "last_validated_date": "2025-10-06T14:45:59+00:00",
+    "last_validated_date": "2025-12-17T13:53:13+00:00",
     "durations_in_seconds": {
-      "setup": 0.01,
-      "call": 2.39,
-      "teardown": 0.02,
-      "total": 2.42
+      "setup": 0.0,
+      "call": 3.0,
+      "teardown": 0.0,
+      "total": 3.0
     }
   },
   "tests/aws/services/cloudwatch/test_cloudwatch.py::TestCloudWatchMultiProtocol::test_basic_operations_multiple_protocols[smithy-rpc-v2-cbor]": {
-    "last_validated_date": "2025-10-06T14:45:56+00:00",
+    "last_validated_date": "2025-12-17T13:53:10+00:00",
     "durations_in_seconds": {
       "setup": 0.0,
-      "call": 2.4,
-      "teardown": 0.02,
-      "total": 2.42
+      "call": 3.15,
+      "teardown": 0.0,
+      "total": 3.15
     }
   },
   "tests/aws/services/cloudwatch/test_cloudwatch.py::TestCloudWatchMultiProtocol::test_exception_serializing_with_no_shape_in_spec[json]": {

diff --git a/tests/aws/services/cloudwatch/utils.py b/tests/aws/services/cloudwatch/utils.py
@@ -5,7 +5,9 @@
 import xmltodict
 from botocore.auth import SigV4Auth
 from botocore.serialize import create_serializer
-from cbor2._decoder import loads as cbor2_loads
+
+# import the unpatched cbor2 on purpose to avoid being polluted by Kinesis-only patches
+from cbor2 import loads as cbor2_loads
 from requests import Response
 
 from localstack import constants
@@ -45,9 +47,9 @@ def _build_headers(self, operation: str, query_mode: bool = False) -> dict: ...
     def _serialize_body(self, body: dict, operation: str) -> str | bytes:
         # here we use the Botocore serializer directly, since it has some complex behavior,
         # and we know CloudWatch supports it by default
-        query_serializer = create_serializer(self.protocol)
+        protocol_serializer = create_serializer(self.protocol)
         operation_model = self.service_model.operation_model(operation)
-        request = query_serializer.serialize_to_request(body, operation_model)
+        request = protocol_serializer.serialize_to_request(body, operation_model)
         return request["body"]
 
     @property

@@ -1452,7 +1452,6 @@ def test_restxml_ignores_get_body():
 def test_smithy_rpc_v2_cbor():
     # we are using a service that LocalStack does not implement yet because it implements `smithy-rpc-v2-cbor`
     # we can replace this service by CloudWatch once it has support in Botocore
-    # TODO: test timestamp parsing
     # example taken from:
     # https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/arc-region-switch/client/create_plan.html
 
@@ -1525,6 +1524,23 @@ def test_smithy_rpc_v2_cbor():
     )
 
 
+def test_rpc_v2_cbor_timestamp_parsing():
+    # This is a real request from the Java SDK v2
+    # It does not encode Timestamps like Botocore: it encodes them as Double of Length 8 (botocore uses Integer)
+    request = HttpRequest(
+        method="POST",
+        path="/v1/service/GraniteServiceVersion20100801/operation/PutMetricData",
+        body=b"\xbfiNamespacelSITE/TRAFFICjMetricData\x81\xbfjMetricNamemPAGES_VISITEDjDimensions\x81\xbfdNamelUNIQUE_PAGESeValuedURLS\xffiTimestamp\xc1\xfbA\xdaP\xaf+\x88\xa3\xd7eValue\xfb?\xf3\xbfg\xf4\xdb\xdf\x8fdUnitdNone\xff\xff",
+    )
+    parser = create_parser(load_service("cloudwatch"), protocol="smithy-rpc-v2-cbor")
+    parsed_operation_model, parsed_request = parser.parse(request)
+    timestamp = parsed_request["MetricData"][0]["Timestamp"]
+    assert isinstance(timestamp, datetime)
+    assert timestamp.microsecond == 135000
+    assert timestamp.minute == 38
+    assert timestamp.tzinfo == UTC
+
+
 @pytest.mark.parametrize("protocol", ("json", "smithy-rpc-v2-cbor"))
 def test_protocol_selection(protocol):
     # we are using a service that LocalStack does not implement yet because it implements `smithy-rpc-v2-cbor`