diff --git a/app/domains/ticket/services.py b/app/domains/ticket/services.py
index 1751ccb..ae16cfb 100644
--- a/app/domains/ticket/services.py
+++ b/app/domains/ticket/services.py
@@ -788,7 +788,10 @@ def _queue_sort_key(self, ticket: Ticket) -> tuple[int, datetime]:
             TicketCriticality.MEDIUM: 1,
             TicketCriticality.LOW: 2,
         }
-        return criticality_priority[ticket.criticality], ticket.creation_date
+        creation_date = ticket.creation_date
+        if creation_date.tzinfo is None:
+            creation_date = creation_date.replace(tzinfo=UTC)
+        return criticality_priority[ticket.criticality], creation_date
 
     def _to_ticket_queue_item_response(self, ticket: Ticket) -> TicketQueueItemResponse:
         current_assignment = self._get_active_assignment(ticket)
diff --git a/scripts/normalize_ticket_datetimes.py b/scripts/normalize_ticket_datetimes.py
new file mode 100644
index 0000000..5ff060a
--- /dev/null
+++ b/scripts/normalize_ticket_datetimes.py
@@ -0,0 +1,134 @@
+import argparse
+import os
+from datetime import UTC, datetime
+from typing import Any
+
+from pymongo import MongoClient
+
+
+DATE_FIELDS = {
+    "creation_date",
+    "assignment_date",
+    "exit_date",
+    "date",
+}
+
+
+def _parse_datetime(value: Any) -> datetime | None:
+    if value is None:
+        return None
+
+    if isinstance(value, datetime):
+        if value.tzinfo is None:
+            return value
+        return value.astimezone(UTC).replace(tzinfo=None)
+
+    if isinstance(value, str):
+        text = value.strip()
+        if text.endswith("Z"):
+            text = text[:-1] + "+00:00"
+        try:
+            parsed = datetime.fromisoformat(text)
+        except ValueError:
+            return None
+        if parsed.tzinfo is None:
+            return parsed
+        return parsed.astimezone(UTC).replace(tzinfo=None)
+
+    return None
+
+
+def _normalize_doc(ticket: dict[str, Any]) -> dict[str, Any]:
+    updated: dict[str, Any] = {}
+
+    creation_date = _parse_datetime(ticket.get("creation_date"))
+    if creation_date is not None:
+        if ticket.get("creation_date") != creation_date:
+            updated["creation_date"] = creation_date
+
+    comments = ticket.get("comments") or []
+    updated_comments = []
+    comments_changed = False
+    for comment in comments:
+        if not isinstance(comment, dict):
+            updated_comments.append(comment)
+            continue
+        new_comment = dict(comment)
+        if "date" in new_comment:
+            normalized = _parse_datetime(new_comment.get("date"))
+            if normalized is not None and new_comment.get("date") != normalized:
+                new_comment["date"] = normalized
+                comments_changed = True
+        updated_comments.append(new_comment)
+
+    if comments_changed:
+        updated["comments"] = updated_comments
+
+    history = ticket.get("agent_history") or []
+    updated_history = []
+    history_changed = False
+    for entry in history:
+        if not isinstance(entry, dict):
+            updated_history.append(entry)
+            continue
+        new_entry = dict(entry)
+        for field in ("assignment_date", "exit_date"):
+            if field in new_entry:
+                normalized = _parse_datetime(new_entry.get(field))
+                if normalized is not None and new_entry.get(field) != normalized:
+                    new_entry[field] = normalized
+                    history_changed = True
+        updated_history.append(new_entry)
+
+    if history_changed:
+        updated["agent_history"] = updated_history
+
+    return updated
+
+
+def _build_mongo_uri() -> str:
+    host = os.getenv("MONGO_HOST", "localhost")
+    port = os.getenv("MONGO_PORT", "27017")
+    user = os.getenv("MONGO_USER", "")
+    password = os.getenv("MONGO_PASSWORD", "")
+
+    if user and password:
+        return (
+            f"mongodb://{user}:{password}@{host}:{port}/"
+            "?authSource=admin"
+        )
+    return f"mongodb://{host}:{port}"
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Normalize ticket datetime fields to UTC naive datetimes."
+    )
+    parser.add_argument("--apply", action="store_true", help="Apply updates")
+    args = parser.parse_args()
+
+    db_name = os.getenv("MONGO_DB", "syncdesk_db")
+    client = MongoClient(_build_mongo_uri())
+    db = client[db_name]
+    tickets = db["tickets"]
+
+    scanned = 0
+    updated = 0
+
+    for ticket in tickets.find({}):
+        scanned += 1
+        changes = _normalize_doc(ticket)
+        if not changes:
+            continue
+        updated += 1
+        if args.apply:
+            tickets.update_one({"_id": ticket["_id"]}, {"$set": changes})
+
+    mode = "applied" if args.apply else "dry-run"
+    print(f"Tickets scanned: {scanned}")
+    print(f"Tickets needing updates: {updated}")
+    print(f"Mode: {mode}")
+
+
+if __name__ == "__main__":
+    main()