fix: use datetime for InvocationCompletedDetails timestamps

Author: bchampp

src/aws_durable_execution_sdk_python_testing/execution.py

@@ -225,7 +225,7 @@ def has_pending_operations(self, execution: Execution) -> bool:
         return False
 
     def record_invocation_completion(
-        self, start_timestamp: float, end_timestamp: float, request_id: str
+        self, start_timestamp: datetime, end_timestamp: datetime, request_id: str
     ) -> None:
         """Record an invocation completion event."""
         self.invocation_completions.append(

src/aws_durable_execution_sdk_python_testing/executor.py

@@ -419,9 +419,7 @@ def get_execution_history(
         for completion in execution.invocation_completions:
             invocation_event = HistoryEvent.create_invocation_completed(
                 event_id=0,  # Temporary, will be reassigned
-                event_timestamp=datetime.fromtimestamp(
-                    completion.end_timestamp, tz=UTC
-                ),
+                event_timestamp=completion.end_timestamp,
                 start_timestamp=completion.start_timestamp,
                 end_timestamp=completion.end_timestamp,
                 request_id=completion.request_id,
@@ -784,13 +782,13 @@ async def invoke() -> None:
 
                 self._store.save(execution)
 
-                invocation_start = time.time()
+                invocation_start = datetime.now(UTC)
                 invoke_response = self._invoker.invoke(
                     execution.start_input.function_name,
                     invocation_input,
                     execution.start_input.lambda_endpoint,
                 )
-                invocation_end = time.time()
+                invocation_end = datetime.now(UTC)
 
                 # Reload execution after invocation in case it was completed via checkpoint
                 execution = self._store.load(execution_arn)

src/aws_durable_execution_sdk_python_testing/model.py

@@ -1227,8 +1227,8 @@ def to_dict(self) -> dict[str, Any]:
 class InvocationCompletedDetails:
     """Invocation completed event details."""
 
-    start_timestamp: float
-    end_timestamp: float
+    start_timestamp: datetime.datetime
+    end_timestamp: datetime.datetime
     request_id: str
 
     @classmethod
@@ -2261,8 +2261,8 @@ def create_invocation_completed(
         cls,
         event_id: int,
         event_timestamp: datetime.datetime,
-        start_timestamp: float,
-        end_timestamp: float,
+        start_timestamp: datetime.datetime,
+        end_timestamp: datetime.datetime,
         request_id: str,
     ) -> Event:
         """Create invocation completed event."""