diff --git a/hindsight-api/hindsight_api/engine/retain/fact_extraction.py b/hindsight-api/hindsight_api/engine/retain/fact_extraction.py
index 9c3c0a73..09d418ce 100644
--- a/hindsight-api/hindsight_api/engine/retain/fact_extraction.py
+++ b/hindsight-api/hindsight_api/engine/retain/fact_extraction.py
@@ -759,6 +759,10 @@ async def _extract_facts_from_chunk(
 
     # Build user message with metadata and chunk content in a clear format
     # Format event_date with day of week for better temporal reasoning
+    # Handle both datetime objects and ISO string formats (from deserialized async tasks)
+    from .orchestrator import parse_datetime_flexible
+
+    event_date = parse_datetime_flexible(event_date)
     event_date_formatted = event_date.strftime("%A, %B %d, %Y")  # e.g., "Monday, June 10, 2024"
     user_message = f"""Extract facts from the following text chunk.
 
@@ -1346,6 +1350,8 @@ def _add_temporal_offsets(facts: list[ExtractedFactType], contents: list[RetainC
 
     Modifies facts in place.
     """
+    from .orchestrator import parse_datetime_flexible
+
     # Group facts by content_index
     current_content_idx = 0
     content_fact_start = 0
@@ -1360,10 +1366,10 @@ def _add_temporal_offsets(facts: list[ExtractedFactType], contents: list[RetainC
         fact_position = i - content_fact_start
         offset = timedelta(seconds=fact_position * SECONDS_PER_FACT)
 
-        # Apply offset to all temporal fields
+        # Apply offset to all temporal fields (handle both datetime objects and ISO strings)
         if fact.occurred_start:
-            fact.occurred_start = fact.occurred_start + offset
+            fact.occurred_start = parse_datetime_flexible(fact.occurred_start) + offset
         if fact.occurred_end:
-            fact.occurred_end = fact.occurred_end + offset
+            fact.occurred_end = parse_datetime_flexible(fact.occurred_end) + offset
         if fact.mentioned_at:
-            fact.mentioned_at = fact.mentioned_at + offset
+            fact.mentioned_at = parse_datetime_flexible(fact.mentioned_at) + offset
diff --git a/hindsight-api/hindsight_api/engine/retain/orchestrator.py b/hindsight-api/hindsight_api/engine/retain/orchestrator.py
index 5e4b0a1d..dec79910 100644
--- a/hindsight-api/hindsight_api/engine/retain/orchestrator.py
+++ b/hindsight-api/hindsight_api/engine/retain/orchestrator.py
@@ -8,6 +8,7 @@ import logging
 import time
 import uuid
 from datetime import UTC, datetime
+from typing import Any
 
 from ..db_utils import acquire_with_retry
 from . import bank_utils
@@ -18,6 +19,39 @@ def utcnow():
     return datetime.now(UTC)
 
 
+def parse_datetime_flexible(value: Any) -> datetime:
+    """
+    Parse a datetime value that could be either a datetime object or an ISO string.
+
+    This handles datetime values from both direct Python calls and deserialized JSON
+    (where datetime objects are serialized as ISO strings).
+
+    Args:
+        value: Either a datetime object or an ISO format string
+
+    Returns:
+        datetime object (timezone-aware)
+
+    Raises:
+        TypeError: If value is neither datetime nor string
+        ValueError: If string is not a valid ISO datetime
+    """
+    if isinstance(value, datetime):
+        # Ensure timezone-aware
+        if value.tzinfo is None:
+            return value.replace(tzinfo=UTC)
+        return value
+    elif isinstance(value, str):
+        # Parse ISO format string (handles both 'Z' and '+00:00' timezone formats)
+        dt = datetime.fromisoformat(value.replace("Z", "+00:00"))
+        # Ensure timezone-aware
+        if dt.tzinfo is None:
+            return dt.replace(tzinfo=UTC)
+        return dt
+    else:
+        raise TypeError(f"Expected datetime or string, got {type(value).__name__}")
+
+
 from ..response_models import TokenUsage
 from . import (
     chunk_storage,
@@ -89,10 +123,18 @@ async def retain_batch(
         # Merge item-level tags with document-level tags
         item_tags = item.get("tags", []) or []
         merged_tags = list(set(item_tags + (document_tags or [])))
+
+        # Handle event_date: parse flexibly (handles both datetime objects and ISO strings)
+        event_date_value = item.get("event_date")
+        if event_date_value:
+            event_date_value = parse_datetime_flexible(event_date_value)
+        else:
+            event_date_value = utcnow()
+
         content = RetainContent(
             content=item["content"],
             context=item.get("context", ""),
-            event_date=item.get("event_date") or utcnow(),
+            event_date=event_date_value,
             metadata=item.get("metadata", {}),
             entities=item.get("entities", []),
             tags=merged_tags,
diff --git a/hindsight-api/tests/test_http_api_integration.py b/hindsight-api/tests/test_http_api_integration.py
index c69bbfef..2a05e98c 100644
--- a/hindsight-api/tests/test_http_api_integration.py
+++ b/hindsight-api/tests/test_http_api_integration.py
@@ -1174,3 +1174,58 @@ async def test_retain_with_multiple_timestamps(api_client, test_bank_id):
     data = response.json()
     assert data["success"] is True
     assert data["items_count"] == 3
+
+
+@pytest.mark.asyncio
+async def test_retain_with_timestamp_async_complete_processing(api_client, test_bank_id):
+    """Test that async retain with timestamp completes full processing including fact extraction."""
+    # Submit async retain with timestamp
+    response = await api_client.post(
+        f"/v1/default/banks/{test_bank_id}/memories",
+        json={
+            "items": [
+                {
+                    "content": "The quarterly meeting was held on January 30th 2026",
+                    "context": "meetings",
+                    "timestamp": "2026-01-30T11:45:00Z"
+                }
+            ],
+            "async": True
+        }
+    )
+    
+    assert response.status_code == 200, f"Expected 200, got {response.status_code}: {response.text}"
+    data = response.json()
+    assert data["success"] is True
+    assert data["async"] is True
+    operation_id = data["operation_id"]
+    
+    # Wait for async processing to complete (poll operation status)
+    max_wait_seconds = 30
+    poll_interval = 0.5
+    elapsed = 0
+    operation_completed = False
+    
+    while elapsed < max_wait_seconds:
+        response = await api_client.get(f"/v1/default/banks/{test_bank_id}/operations/{operation_id}")
+        if response.status_code == 200:
+            op_status = response.json()
+            if op_status.get("status") == "completed":
+                operation_completed = True
+                break
+            elif op_status.get("status") == "failed":
+                raise AssertionError(f"Operation failed: {op_status.get('error_message')}")
+        
+        await asyncio.sleep(poll_interval)
+        elapsed += poll_interval
+    
+    assert operation_completed, f"Async operation did not complete within {max_wait_seconds} seconds"
+    
+    # Verify memories were actually stored
+    response = await api_client.get(
+        f"/v1/default/banks/{test_bank_id}/memories/list",
+        params={"limit": 10}
+    )
+    assert response.status_code == 200
+    items = response.json()["items"]
+    assert len(items) > 0, "Should have stored memories after async processing"
diff --git a/uv.lock b/uv.lock
index 9f764038..dac1cdf0 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1295,7 +1295,7 @@ wheels = [
 
 [[package]]
 name = "hindsight-all"
-version = "0.4.3"
+version = "0.4.4"
 source = { editable = "hindsight" }
 dependencies = [
     { name = "hindsight-api" },
@@ -1319,7 +1319,7 @@ provides-extras = ["test"]
 
 [[package]]
 name = "hindsight-api"
-version = "0.4.3"
+version = "0.4.4"
 source = { editable = "hindsight-api" }
 dependencies = [
     { name = "aiohttp" },
@@ -1449,7 +1449,7 @@ dev = [
 
 [[package]]
 name = "hindsight-client"
-version = "0.4.3"
+version = "0.4.4"
 source = { editable = "hindsight-clients/python" }
 dependencies = [
     { name = "aiohttp" },
@@ -1483,7 +1483,7 @@ provides-extras = ["test"]
 
 [[package]]
 name = "hindsight-dev"
-version = "0.4.3"
+version = "0.4.4"
 source = { editable = "hindsight-dev" }
 dependencies = [
     { name = "hindsight-api" },
@@ -1529,7 +1529,7 @@ dev = [
 
 [[package]]
 name = "hindsight-embed"
-version = "0.4.3"
+version = "0.4.4"
 source = { editable = "hindsight-embed" }
 dependencies = [
     { name = "httpx" },