diff --git a/CHANGELOG b/CHANGELOG
index 168ad50053..e218b7ad2f 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,5 @@
+* Call on_change methods after setting default dtstart on calendar view
+
 Version 4.8.0 - 2018-04-23
 * Bug fixes (see mercurial logs for details)
 * Manage active field on search widget
diff --git a/tryton/gui/window/view_form/view/calendar_gtk/calendar_.py b/tryton/gui/window/view_form/view/calendar_gtk/calendar_.py
index e3cb7741cd..f1d8212163 100644
--- a/tryton/gui/window/view_form/view/calendar_gtk/calendar_.py
+++ b/tryton/gui/window/view_form/view/calendar_gtk/calendar_.py
@@ -22,6 +22,8 @@ class Calendar_(goocalendar.Calendar):
         dtstart = self.attrs['dtstart']
         record[dtstart].set(record, datetime.datetime.combine(selected_date,
             datetime.time(0)))
+        record.on_change([dtstart])
+        record.on_change_with([dtstart])
 
     def get_displayed_period(self):
         cal = calendar.Calendar(self.firstweekday)