diff --git a/changelog/52_UNRELEASED_2019-xx-xx.md b/changelog/52_UNRELEASED_2019-xx-xx.md
index e9f4dcbe..e98e2f51 100644
--- a/changelog/52_UNRELEASED_2019-xx-xx.md
+++ b/changelog/52_UNRELEASED_2019-xx-xx.md
@@ -39,6 +39,7 @@
 
 ### General improvements/fixes
 - Added a new `config.php` setting `CALENDAR_SHOW_WEEK_OF_YEAR` to configure if calendars should show week numbers (defaults to `true`)
+- Fixed that datetimepickers not considered the `config.php` setting `CALENDAR_FIRST_DAY_OF_WEEK`
 - Improved the handling which entry page to use with disabled feature flags (thanks @nielstholenaar)
 - Boolean settings provided via environment variables (so the strings `true` and `false`) are now parsed correctly (thanks @mduret)
 - All uploaded pictures (currently for products and recipes) are now automatically downscaled to the appropriate size when serving them to improve page load times
diff --git a/public/js/grocy.js b/public/js/grocy.js
index b2f13fff..8d515c08 100644
--- a/public/js/grocy.js
+++ b/public/js/grocy.js
@@ -535,3 +535,12 @@ function LoadImagesLazy()
 	});
 }
 LoadImagesLazy();
+
+if (!Grocy.CalendarFirstDayOfWeek.isEmpty())
+{
+	moment.updateLocale(moment.locale(), {
+		week: {
+			dow: Grocy.CalendarFirstDayOfWeek
+		}
+	});
+}