diff --git a/addons/web_calendar/static/src/js/web_calendar.js b/addons/web_calendar/static/src/js/web_calendar.js
index 93dfc195e77ea1061c03b591df3ccd06202304bc..4d113ebe588768ae9461bdca03251316405304d0 100644
--- a/addons/web_calendar/static/src/js/web_calendar.js
+++ b/addons/web_calendar/static/src/js/web_calendar.js
@@ -42,7 +42,7 @@ function get_fc_defaultOptions() {
         weekNumbers: true,
         titleFormat: {
             month: 'MMMM yyyy',
-            week: "W",
+            week: "w",
             day: dateFormat,
         },
         columnFormat: {