diff --git a/addons/web/static/src/js/view_form.js b/addons/web/static/src/js/view_form.js
index 1321be93ca7..ec92cd2ac52 100644
--- a/addons/web/static/src/js/view_form.js
+++ b/addons/web/static/src/js/view_form.js
@@ -135,21 +135,21 @@ openerp.web.FormView = openerp.web.View.extend( /** @lends openerp.web.FormView#
     },
 
     do_show: function () {
-        var self = this,
-            deferred = $.Deferred().resolve();
-        this.has_been_loaded.then(function() {
+        var self = this;
+        return this.has_been_loaded.pipe(function() {
+            var result;
             if (self.dataset.index === null) {
                 // null index means we should start a new record
-                deferred.pipe(self.on_button_new());
+                result = self.on_button_new();
             } else {
-                deferred.pipe(self.dataset.read_index(_.keys(self.fields_view.fields)).pipe(self.on_record_loaded));
+                result = self.dataset.read_index(_.keys(self.fields_view.fields)).pipe(self.on_record_loaded);
             }
             self.$element.show();
             if (self.sidebar) {
                 self.sidebar.$element.show();
             }
+            return result;
         });
-        return deferred;
     },
     do_hide: function () {
         this._super();
@@ -172,7 +172,7 @@ openerp.web.FormView = openerp.web.View.extend( /** @lends openerp.web.FormView#
                 field.validate();
             });
         });
-        return $.when.apply(null, set_values).then(function() {
+        return $.when.apply(null, set_values).pipe(function() {
             if (!record.id) {
                 self.show_invalid = false;
                 // New record: Second pass in order to trigger the onchanges
diff --git a/addons/web_calendar/static/src/js/calendar.js b/addons/web_calendar/static/src/js/calendar.js
index 304a6861782..1dda62b3802 100644
--- a/addons/web_calendar/static/src/js/calendar.js
+++ b/addons/web_calendar/static/src/js/calendar.js
@@ -288,7 +288,9 @@ openerp.web_calendar.CalendarView = openerp.web.View.extend({
         var self = this,
             data = this.get_event_data(event_obj),
             form = self.form_dialog.form,
-            fields_to_fetch = _(form.fields_view.fields).keys();
+            fields_to_fetch = _(form.fields_view.fields).keys(),
+            set_values = [], 
+            fields_names = [];
         this.dataset.index = null;
         self.creating_event_id = event_id;
         this.form_dialog.form.do_show().then(function() {
@@ -296,14 +298,26 @@ openerp.web_calendar.CalendarView = openerp.web.View.extend({
             _.each(['date_start', 'date_stop', 'date_delay'], function(field) {
                 var field_name = self[field];
                 if (field_name && form.fields[field_name]) {
-                    field = form.fields[field_name];
-                    field.set_value(data[field_name]);
-                    field.dirty = true;
-                    form.do_onchange(field);
+                    var ffield = form.fields[field_name];
+                    ffield.reset();
+                    var result = ffield.set_value(data[field_name]);
+                    set_values.push(result);
+                    fields_names.push(field_name);
+                    $.when(result).then(function() {
+                        ffield.validate();
+                    });
                 }
             });
-            form.show_invalid = true;
-            self.form_dialog.open();
+
+            $.when(set_values).then(function() {
+                _.each(fields_names, function(fn) {
+                    var field = form.fields[fn];
+                    field.dirty = true;
+                    form.do_onchange(field);
+                });
+                form.show_invalid = true;
+                self.form_dialog.open();
+            });
         });
     },
     do_save_event: function(event_id, event_obj) {