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 caa1d26e8c6..20c067d2ccc 100644
--- a/addons/web/static/src/js/views/calendar/calendar_model.js
+++ b/addons/web/static/src/js/views/calendar/calendar_model.js
@@ -94,7 +94,7 @@ return AbstractModel.extend({
         if (this.mapping.all_day) {
             if (event.record) {
                 data[this.mapping.all_day] =
-                    (this.scale !== 'month' && event.allDay) ||
+                    (this.data.scale !== 'month' && event.allDay) ||
                     event.record[this.mapping.all_day] &&
                     end.diff(start) < 10 ||
                     false;
@@ -758,18 +758,7 @@ return AbstractModel.extend({
             'attendees':attendees,
         };
 
-        if (this.mapping.all_day && evt[this.mapping.all_day]) {
-            // r.start = date_start.format('YYYY-MM-DD');
-            // r.end = date_stop.format('YYYY-MM-DD');
-        } else if (this.data.scale === 'month' && this.fields[this.mapping.date_start].type !== 'date') {
-            // In month, FullCalendar gives the end day as the
-            // next day at midnight (instead of 23h59).
-            date_stop.add(1, 'days');
-
-            // allow to resize in month mode
-            r.reset_allday = r.allDay;
-            r.start = date_start.toDate();
-            r.end = date_stop.startOf('day').toDate();
+        if (!(this.mapping.all_day && evt[this.mapping.all_day]) && this.data.scale === 'month' && this.fields[this.mapping.date_start].type !== 'date') {
             r.showTime = true;
         }
 
diff --git a/addons/web/static/src/js/views/calendar/calendar_renderer.js b/addons/web/static/src/js/views/calendar/calendar_renderer.js
index f6ae085e81a..4f492585ef1 100644
--- a/addons/web/static/src/js/views/calendar/calendar_renderer.js
+++ b/addons/web/static/src/js/views/calendar/calendar_renderer.js
@@ -338,7 +338,6 @@ return AbstractRenderer.extend({
                 event = Object.assign({}, event, {
                     r_start: fc4Event.extendedProps.r_start && moment(fc4Event.extendedProps.r_start).utcOffset(0, true),
                     r_end: fc4Event.extendedProps.r_end && moment(fc4Event.extendedProps.r_end).utcOffset(0, true),
-                    reset_allday: fc4Event.extendedProps.reset_allday,
                     record: fc4Event.extendedProps.record,
                     attendees: fc4Event.extendedProps.attendees,
                 });
diff --git a/addons/web/static/tests/views/calendar_tests.js b/addons/web/static/tests/views/calendar_tests.js
index b6debe56f58..0de9c8e09dc 100644
--- a/addons/web/static/tests/views/calendar_tests.js
+++ b/addons/web/static/tests/views/calendar_tests.js
@@ -2857,6 +2857,67 @@ QUnit.module('Views', {
         calendar.destroy();
     });
 
+    QUnit.test("drag and drop on month mode with all_day mapping", async function (assert) {
+        // Same test as before but in calendarEventToRecord (calendar_model.js) there is
+        // different condition branching with all_day mapping or not
+        assert.expect(2);
+
+        const calendar = await createCalendarView({
+            arch:
+                `<calendar date_start="start" date_stop="stop" mode="month" event_open_popup="true" quick_add="False" all_day="allday">
+                    <field name="name"/>
+                    <field name="partner_id"/>
+                </calendar>`,
+            archs: archs,
+            data: this.data,
+            model: 'event',
+            View: CalendarView,
+            viewOptions: { initialDate: initialDate },
+        });
+
+        // Create event (on 20 december)
+        var $cell = calendar.$('.fc-day-grid .fc-row:eq(3) .fc-day:eq(2)');
+        testUtils.triggerMouseEvent($cell, "mousedown");
+        testUtils.triggerMouseEvent($cell, "mouseup");
+        await testUtils.nextTick();
+        var $input = $('.modal-body input:first');
+        await testUtils.fields.editInput($input, "An event");
+        await testUtils.dom.click($('.o_field_widget[name="allday"] input'));
+        await testUtils.nextTick();
+
+        // use datepicker to enter a date: 12/20/2016 07:00:00
+        testUtils.dom.openDatepicker($('.o_field_widget[name="start"].o_datepicker'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .picker-switch a[data-action="togglePicker"]'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .timepicker .timepicker-hour'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .timepicker-hours td.hour:contains(07)'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .picker-switch a[data-action="close"]'));
+
+        // use datepicker to enter a date: 12/20/2016 19:00:00
+        testUtils.dom.openDatepicker($('.o_field_widget[name="stop"].o_datepicker'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .picker-switch a[data-action="togglePicker"]'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .timepicker .timepicker-hour'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .timepicker-hours td.hour:contains(19)'));
+        await testUtils.dom.click($('.bootstrap-datetimepicker-widget .picker-switch a[data-action="close"]'));
+
+        await testUtils.dom.click($('.modal button.btn-primary'));
+        await testUtils.nextTick();
+
+        // Move event to another day (on 19 december)
+        await testUtils.dragAndDrop(
+            calendar.$('.fc-event:contains("An event")'),
+            calendar.$('.fc-day-grid .fc-row:eq(3) .fc-day-top:eq(1)')
+        );
+        await testUtils.nextTick();
+        await testUtils.dom.click(calendar.$('.fc-event:contains("An event")'));
+
+        assert.containsOnce(calendar, '.popover:contains("07:00")',
+            "start hour shouldn't have been changed");
+        assert.containsOnce(calendar, '.popover:contains("19:00")',
+            "end hour shouldn't have been changed");
+
+        calendar.destroy();
+    });
+
     QUnit.test('drag and drop on month mode with date_start and date_delay', async function (assert) {
         assert.expect(1);