diff --git a/addons/web/static/src/js/views/calendar/calendar_model.js b/addons/web/static/src/js/views/calendar/calendar_model.js
index e338ae55ece..5be6b74e1de 100644
--- a/addons/web/static/src/js/views/calendar/calendar_model.js
+++ b/addons/web/static/src/js/views/calendar/calendar_model.js
@@ -38,17 +38,29 @@ return AbstractModel.extend({
         var start = event.start.clone();
         var end = event.end && event.end.clone();
 
-        if (!end || end.diff(start) < 0) {
-            end = start.clone().add(1, 'h');
+        // Detects allDay events (86400000 = 1 day in ms)
+        if (event.allDay || (end && end.diff(start) % 86400000 === 0)) {
+            event.allDay = true;
         }
 
-        if (event.allDay || end.diff(start) % 86400000 === 0) {
-            event.allDay = true;
+        // Set end date if not existing
+        if (!end || end.diff(start) < 0) { // undefined or invalid end date
+            if (event.allDay) {
+                end = start.clone();
+            } else {
+                // in week mode or day mode, convert allday event to event
+                end = start.clone().add(2, 'h');
+            }
+        } else if (event.allDay) {
+            // For an "allDay", FullCalendar gives the end day as the
+            // next day at midnight (instead of 23h59).
+            end.add(-1, 'days');
+        }
 
-            if (this.data.scale === 'month') {
-                // In month, FullCalendar gives the end day as the
-                // next day at midnight (instead of 23h59).
-                end.add(-1, 'days');
+        // An "allDay" event without the "all_day" option is not considered
+        // as a 24h day. It's just a part of the day (by default: 7h-19h).
+        if (event.allDay) {
+            if (!this.mapping.all_day) {
                 if (event.r_start) {
                     start.hours(event.r_start.hours())
                          .minutes(event.r_start.minutes())
@@ -58,21 +70,11 @@ return AbstractModel.extend({
                        .minutes(event.r_end.minutes())
                        .seconds(event.r_end.seconds())
                        .utc();
-                } else if (this.mapping.all_day) {
-                    start.utc();
-                    end.utc();
                 } else {
                     // default hours in the user's timezone
                     start.hours(7).add(-this.getSession().getTZOffset(start), 'minutes');
                     end.hours(19).add(-this.getSession().getTZOffset(end), 'minutes');
                 }
-            } else if (this.mapping.all_day) {
-                start.startOf('day');
-                end.startOf('day').add(-1, 'days');
-            } else {
-                // default hours in the user's timezone
-                start.hours(7).add(-this.getSession().getTZOffset(start), 'minutes');
-                end.hours(19).add(-this.getSession().getTZOffset(end), 'minutes');
             }
         } else {
             start.add(-this.getSession().getTZOffset(start), 'minutes');
diff --git a/addons/web/static/tests/views/calendar_tests.js b/addons/web/static/tests/views/calendar_tests.js
index 31891d6c28b..9f9be3a4042 100644
--- a/addons/web/static/tests/views/calendar_tests.js
+++ b/addons/web/static/tests/views/calendar_tests.js
@@ -509,7 +509,7 @@ QUnit.module('Views', {
     });
 
     QUnit.test('create event with timezone in week mode with formViewDialog', function (assert) {
-        assert.expect(7);
+        assert.expect(8);
 
         this.data.event.records = [];
         this.data.event.onchanges = {
@@ -558,12 +558,8 @@ QUnit.module('Views', {
                     "should send the context to create events");
                 }
                 if (args.method === "write") {
-                    assert.deepEqual(args.args[1], {
-                          "allday": false,
-                          "start": "2016-12-12 06:00:00",
-                          "stop": "2016-12-12 08:00:00"
-                        },
-                    "should move the event");
+                    assert.deepEqual(args.args[1], expectedEvent,
+                        "should move the event");
                 }
                 return this._super(route, args);
             },
@@ -635,11 +631,28 @@ QUnit.module('Views', {
         left = pos.left + 5;
         top = pos.top + 5;
 
+        // Mode this event to another day
+        var expectedEvent = {
+          "allday": false,
+          "start": "2016-12-12 06:00:00",
+          "stop": "2016-12-12 08:00:00"
+        };
         testUtils.triggerPositionalMouseEvent(left, top, "mousedown");
         left = calendar.$('.fc-day:eq(1)').offset().left + 5;
         testUtils.triggerPositionalMouseEvent(left, top, "mousemove");
         testUtils.triggerPositionalMouseEvent(left, top, "mouseup");
 
+        // Move to "All day"
+        expectedEvent = {
+          "allday": true,
+          "start": "2016-12-12 00:00:00",
+          "stop": "2016-12-12 00:00:00"
+        };
+        testUtils.triggerPositionalMouseEvent(left, top, "mousedown");
+        top = calendar.$('.fc-day:eq(1)').offset().top + 5;
+        testUtils.triggerPositionalMouseEvent(left, top, "mousemove");
+        testUtils.triggerPositionalMouseEvent(left, top, "mouseup");
+
         calendar.destroy();
         $view.remove();
     });
@@ -714,6 +727,65 @@ QUnit.module('Views', {
         $view.remove();
     });
 
+    QUnit.test('create all day event in week mode (no quickCreate)', function (assert) {
+        assert.expect(1);
+
+        this.data.event.records = [];
+
+        var calendar = createView({
+            View: CalendarView,
+            model: 'event',
+            data: this.data,
+            arch:
+            '<calendar class="o_calendar_test" '+
+                'date_start="start" '+
+                'date_stop="stop" '+
+                'mode="week" '+
+                'quick_add="False" '+
+                'readonly_form_view_id="1">'+
+                    '<field name="name"/>'+
+            '</calendar>',
+            archs: archs,
+            viewOptions: {
+                initialDate: initialDate,
+            },
+            session: {
+                getTZOffset: function () {
+                    return 120;
+                },
+            },
+            intercepts: {
+                do_action: function (event) {
+                    assert.deepEqual(event.data.action.context, {
+                        "default_name": null,
+                        "default_start": "2016-12-14 05:00:00",
+                        "default_stop": "2016-12-15 17:00:00",
+                    },
+                    "should send the correct data to create events");
+                },
+            },
+        });
+
+        var $view = $('#qunit-fixture').contents();
+        $view.prependTo('body'); // => select with click position
+
+
+        var pos = calendar.$('.fc-bg td:eq(4)').offset();
+        try {
+            testUtils.triggerPositionalMouseEvent(pos.left+15, pos.top+15, "mousedown");
+        } catch (e) {
+            calendar.destroy();
+            $view.remove();
+            throw new Error('The test fails to simulate a click in the screen. Your screen is probably too small or your dev tools is open.');
+        }
+        pos = calendar.$('.fc-bg td:eq(5)').offset();
+        testUtils.triggerPositionalMouseEvent(pos.left+15, pos.top+15, "mousemove");
+        testUtils.triggerPositionalMouseEvent(pos.left+15, pos.top+15, "mouseup");
+
+        calendar.destroy();
+        $view.remove();
+    });
+
     QUnit.test('create event in month mode', function (assert) {
         assert.expect(4);