diff --git a/beesdoo_shift/wizard/holiday.py b/beesdoo_shift/wizard/holiday.py
index 3d387fa..b95bdc2 100644
--- a/beesdoo_shift/wizard/holiday.py
+++ b/beesdoo_shift/wizard/holiday.py
@@ -10,9 +10,9 @@ class Subscribe(models.TransientModel):
 
     @api.multi
     def holidays(self):
-        self = self._check() #maybe a different group
+        self = self._check()  # maybe a different group
         status_id = self.env['cooperative.status'].search([('cooperator_id', '=', self.cooperator_id.id)])
-        if status_id.holiday_end_time >= status_id.today:
+        if status_id.holiday_end_time and status_id.holiday_end_time >= status_id.today:
             raise ValidationError(_("You cannot encode new holidays since the previous holidays encoded are not over yet"))
         status_id.sudo().write({'holiday_start_time': self.holiday_start_day, 'holiday_end_time': self.holiday_end_day})
         self.env['beesdoo.shift.shift'].sudo().unsubscribe_from_today([self.cooperator_id.id], today=self.holiday_start_day, end_date=self.holiday_end_day)