diff --git a/app/helper/message.py b/app/helper/message.py
index 8f3a2637..c7427f35 100644
--- a/app/helper/message.py
+++ b/app/helper/message.py
@@ -64,6 +64,8 @@ class MessageQueueManager(metaclass=SingletonClass):
         for period in periods:
             if not period:
                 continue
+            if not period.get('start') or not period.get('end'):
+                continue
             start_h, start_m = map(int, period['start'].split(':'))
             end_h, end_m = map(int, period['end'].split(':'))
             parsed.append((start_h, start_m, end_h, end_m))