Query MongoDB timestamps using normalized ISO string bounds

great_ai/helper/normalise_datetime.py

@@ -0,0 +1,8 @@
+from datetime import datetime, timezone
+
+
+def normalise_datetime(value: datetime) -> datetime:
+    """Interpret naive timestamps as UTC and normalize aware timestamps to UTC."""
+    return (
+        value.astimezone(timezone.utc).replace(tzinfo=None) if value.tzinfo else value
+    )