diff --git a/addons/web_calendar/static/src/js/calendar.js b/addons/web_calendar/static/src/js/calendar.js
index dcc9edf5644..2cc0cae1392 100644
--- a/addons/web_calendar/static/src/js/calendar.js
+++ b/addons/web_calendar/static/src/js/calendar.js
@@ -180,11 +180,11 @@ openerp.web_calendar.CalendarView = openerp.web.View.extend({
                 }
             }
 
-            if (this.fields[this.date_start]['type'] == 'date' && /^\d\d\d\d-\d\d-\d\d$/.exec(evt[this.date_start])) {
-                evt[this.date_start] = openerp.web.str_to_date(evt[this.date_start]).set({hour: 9}).toString('yyyy-MM-dd HH:mm:ss');
+            if (this.fields[this.date_start]['type'] == 'date') {
+                evt[this.date_start] = openerp.web.auto_str_to_date(evt[this.date_start]).set({hour: 9}).toString('yyyy-MM-dd HH:mm:ss');
             }
             if (this.date_stop && evt[this.date_stop] && this.fields[this.date_stop]['type'] == 'date') {
-                evt[this.date_stop] = openerp.web.str_to_date(evt[this.date_stop]).set({hour: 17}).toString('yyyy-MM-dd HH:mm:ss');
+                evt[this.date_stop] = openerp.web.auto_str_to_date(evt[this.date_stop]).set({hour: 17}).toString('yyyy-MM-dd HH:mm:ss');
             }
             res_events.push(this.convert_event(evt));
         }