diff --git a/addons/hr_holidays/static/src/views/calendar/year/calendar_year_renderer.js b/addons/hr_holidays/static/src/views/calendar/year/calendar_year_renderer.js
index 75985607dd2..cdfd919778e 100644
--- a/addons/hr_holidays/static/src/views/calendar/year/calendar_year_renderer.js
+++ b/addons/hr_holidays/static/src/views/calendar/year/calendar_year_renderer.js
@@ -44,6 +44,7 @@ export class TimeOffCalendarYearRenderer extends CalendarYearRenderer {
             weekNumbers: true,
             weekNumbersWithinDays: false,
             weekLabel: _t("Week"),
+            firstDay: 0,
         });
     }