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 a404b618480..403d828d824 100644
--- a/addons/web/static/src/js/views/calendar/calendar_model.js
+++ b/addons/web/static/src/js/views/calendar/calendar_model.js
@@ -452,7 +452,7 @@ return AbstractModel.extend({
             dayNamesShort: moment.weekdaysShort(),
             firstDay: this.week_start,
             slotLabelFormat: _t.database.parameters.time_format.search("%H") !== -1 ? format24Hour : format12Hour,
-            allDaySlot: this.mapping.all_day,
+            allDaySlot: this.mapping.all_day || this.fields[this.mapping.date_start].type === 'date',
         };
     },
     /**
diff --git a/addons/web/static/tests/views/calendar_tests.js b/addons/web/static/tests/views/calendar_tests.js
index c27ac85f498..7b69e8ce167 100644
--- a/addons/web/static/tests/views/calendar_tests.js
+++ b/addons/web/static/tests/views/calendar_tests.js
@@ -2468,6 +2468,26 @@ QUnit.module('Views', {
         calendar.destroy();
     });
 
+    QUnit.test('set event as all day when field is date (without all_day mapping)', async function (assert) {
+        assert.expect(1);
+
+        this.data.event.records[0].start_date = "2016-12-14";
+
+        var calendar = await createCalendarView({
+            View: CalendarView,
+            model: 'event',
+            data: this.data,
+            arch: `<calendar date_start="start_date" mode="week"></calendar>`,
+            archs: archs,
+            viewOptions: {
+                initialDate: initialDate,
+            },
+        });
+        assert.containsOnce(calendar, '.fc-day-grid .fc-event-container',
+            "should be one event in the all day row");
+        calendar.destroy();
+    });
+
     QUnit.test('quickcreate avoid double event creation', async function (assert) {
         assert.expect(1);
         var createCount = 0;