diff --git a/addons/base_action_rule/base_action_rule_view.xml b/addons/base_action_rule/base_action_rule_view.xml
index 21bf6a0b0c9..413f9fdadb6 100644
--- a/addons/base_action_rule/base_action_rule_view.xml
+++ b/addons/base_action_rule/base_action_rule_view.xml
@@ -36,7 +36,7 @@
                                         domain="[('model_id','=',model), ('user_id', '=', False)]"
                                         context="{'default_model_id': model}"/>
                                     <field name="trg_date_id"
-                                        attrs="{'invisible': [('kind', '!=', 'on_time')]}"/>
+                                        attrs="{'invisible': [('kind', '!=', 'on_time')], 'required': [('kind', '=', 'on_time')]}"/>
                                     <label for="trg_date_range" string="Delay After Trigger Date"
                                         attrs="{'invisible': [('trg_date_id','=',False)]}"/>
                                     <div attrs="{'invisible': [('trg_date_id','=',False)]}">