now doing dates and foreign keyed objects corretly

core/utils.py

@@ -9,8 +9,8 @@ import resource
 import socket
 import string
 import subprocess
-from datetime import datetime, timezone
-from decimal import getcontext
+from datetime import datetime, timezone, date
+from decimal import getcontext, Decimal
 from pathlib import Path
 
 from django.contrib.auth.models import User
@@ -540,7 +540,7 @@ class WriteAndCommitError(Exception):
 class CustomJSONEncoder(json.JSONEncoder):
     def default(self, obj):
         # Convert datetime objects to ISO 8601 string format
-        if isinstance(obj, datetime):
+        if isinstance(obj, (datetime, date)):
             return obj.isoformat()
         # Convert Decimal objects to string
         if isinstance(obj, Decimal):