diff --git a/yaltik_crm_action/models/calendar_event.py b/yaltik_crm_action/models/calendar_event.py
index ffa4162..5774a59 100644
--- a/yaltik_crm_action/models/calendar_event.py
+++ b/yaltik_crm_action/models/calendar_event.py
@@ -18,7 +18,7 @@
 
 """ Calendar Event adaptations """
 
-from odoo import models, fields
+from odoo import models, fields, api
 
 
 class CalendarEvent(models.Model):
@@ -26,3 +26,14 @@ class CalendarEvent(models.Model):
     _inherit = 'calendar.event'
 
     partner_location_id = fields.Many2one('res.partner', 'Partner location')
+    crm_action_ids = fields.One2many('crm.action', 'event_id')
+
+    @api.multi
+    def write(self, vals):
+        """ Ensures date action coherence """
+        super(CalendarEvent, self).write(vals)
+        if 'start' in vals:
+            for event in self:
+                if event.crm_action_ids:
+                    event.crm_action_ids.write({'date': event.start})
+        return True
diff --git a/yaltik_crm_action/models/crm_action.py b/yaltik_crm_action/models/crm_action.py
index c10efed..d568154 100644
--- a/yaltik_crm_action/models/crm_action.py
+++ b/yaltik_crm_action/models/crm_action.py
@@ -18,6 +18,7 @@
 
 """ CRM Action """
 
+from datetime import timedelta
 from odoo import models, fields, api, _
 
 
@@ -124,6 +125,22 @@ class CrmAction(models.Model):
                 action.event_id = False
                 event.unlink()
 
+    @api.multi
+    def write(self, vals):
+        """ Ensures date event and basic partner_id coherence """
+        super(CrmAction, self).write(vals)
+        for action in self:
+            if action.event_id:
+                if action.event_id.start != action.date:
+                    stop = fields.Datetime.from_string(action.date) + \
+                        timedelta(hours=action.event_id.duration)
+                    action.event_id.write({'start': action.date,
+                                           'stop': fields.Datetime.to_string(stop)})
+                if action.partner_id and \
+                        action.partner_id not in action.event_id.partner_ids:
+                    action.event_id.partner_ids |= action.partner_id
+        return True
+
 
 class CrmActionType(models.Model):
     """ CRM Action Type """