Update when-then-rules.md

Added left hand side conditions

docs/user-guide/rules-and-forecasting/when-then-rules.md

@@ -8,9 +8,13 @@ When-Then rules are used in combination with the or-rules UI component. They are
 
 ![Manager Rules Editor](img/rules-editor.png)
 
-
 ## Supported actions
 
+On the left hand side you can have conditions for triggering:
+- Attribute value conditions
+- Timer, inluding time of day, sunset, sunrise twilight.
+- Duration: the number of minutes the attribute value condition or timer condition needs to be true
+
 On the right hand side you can trigger different types of actions:
 - Update attribute values
 - Send push- and email notifications to users, assets, or users linked to the asset triggering the rule. Notifications support multi-language notification based on the users preferred language. For details see [Appearance page](../manager-ui/manager-ui.md#appearance).