Allow scheduling notification rules

core/forms.py

@@ -100,7 +100,7 @@ class NotificationRuleForm(RestrictedFormMixin, ModelForm):
             "topic": "The topic to send notifications to. Leave blank for default.",
             "enabled": "Whether the rule is enabled.",
             "data": "The notification rule definition.",
-            "interval": "How often to run the search. On demand only evaluates messages as they are received.",
+            "interval": "How often to run the search. On demand evaluates messages as they are received, without running a scheduled search. The remaining options schedule a search of the database with the window below.",
             "window": "Time window to search: 1d, 1h, 1m, 1s, etc.",
         }