diff --git a/runtime/refactor_baseline_v1.yaml b/runtime/refactor_baseline_v1.yaml
index ed753cb..ce0a6f6 100644
--- a/runtime/refactor_baseline_v1.yaml
+++ b/runtime/refactor_baseline_v1.yaml
@@ -1,9 +1,9 @@
 {
   "formula_id": "AUDIT_REPOSITORY_ENTROPY_V2",
   "gate": "PASS",
-  "total_file_count": 1697,
+  "total_file_count": 1703,
   "package_script_count": 17,
-  "temp_json_count": 159,
+  "temp_json_count": 160,
   "budget": {
     "schema_version": "repository_entropy_budget.v1",
     "max_total_files": 2200,
@@ -15,5 +15,5 @@
       "keep package scripts within release envelope"
     ]
   },
-  "source_zip_sha256": "4de4a7b1217ef5d5375b3b1ea1209f738719e79c4c3c0954e9e96a9dc0d8607e"
+  "source_zip_sha256": "b992c6e54eae1b3b5ccf822d25a902dfcf10dc7a4fec93a902ff920d1cbd02b0"
 }
\ No newline at end of file
diff --git a/src/quant_engine/convert_xlsx_to_json.py b/src/quant_engine/convert_xlsx_to_json.py
index f0c6854..e2b08db 100644
--- a/src/quant_engine/convert_xlsx_to_json.py
+++ b/src/quant_engine/convert_xlsx_to_json.py
@@ -115,7 +115,7 @@ def clean_scalar(value: Any) -> Any:
         return None
     if isinstance(value, float) and math.isnan(value):
         return None
-    if isinstance(value, (pd.Timestamp, dt.datetime, dt.date)):
+    if isinstance(value, (pd.Timestamp, dt.datetime, dt.date, dt.time)):
         return value.isoformat()
     if hasattr(value, "item"):
         try:
@@ -125,6 +125,17 @@ def clean_scalar(value: Any) -> Any:
     return value
 
 
+def _json_default(value: Any) -> Any:
+    if isinstance(value, (pd.Timestamp, dt.datetime, dt.date, dt.time)):
+        return value.isoformat()
+    if hasattr(value, "item"):
+        try:
+            return _json_default(value.item())
+        except Exception:
+            pass
+    return str(value)
+
+
 def normalize_code(value: Any) -> str:
     value = clean_scalar(value)
     if value in (None, ""):
@@ -1585,7 +1596,7 @@ def convert_xlsx_to_json(xlsx_path: Path, output_path: Path) -> None:
         # Recompute checksum invariants after any blueprint mutation patch.
         result["data"]["_harness_context"] = ensure_extended_harness_defaults(result["data"]["_harness_context"])
 
-    output_path.write_text(json.dumps(result, ensure_ascii=False, indent=2), encoding="utf-8")
+    output_path.write_text(json.dumps(result, ensure_ascii=False, indent=2, default=_json_default), encoding="utf-8")
     print(f"Conversion complete: {output_path}")