diff --git a/src/test/java/com/flowingcode/addons/ycalendar/LocaleSelector.java b/src/test/java/com/flowingcode/addons/ycalendar/LocaleSelector.java
new file mode 100644
index 0000000..f9d00cc
--- /dev/null
+++ b/src/test/java/com/flowingcode/addons/ycalendar/LocaleSelector.java
@@ -0,0 +1,60 @@
+/*-
+ * #%L
+ * Year Month Calendar Add-on
+ * %%
+ * Copyright (C) 2021 - 2024 Flowing Code
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package com.flowingcode.addons.ycalendar;
+
+import com.vaadin.flow.component.Composite;
+import com.vaadin.flow.component.datepicker.DatePicker;
+import com.vaadin.flow.component.datepicker.DatePicker.DatePickerI18n;
+import com.vaadin.flow.component.radiobutton.RadioButtonGroup;
+import com.vaadin.flow.function.SerializableConsumer;
+import java.text.DateFormatSymbols;
+import java.time.DayOfWeek;
+import java.time.temporal.WeekFields;
+import java.util.List;
+import java.util.Locale;
+
+@SuppressWarnings("serial")
+public class LocaleSelector extends Composite<RadioButtonGroup<Locale>> {
+
+  private final SerializableConsumer<DatePicker.DatePickerI18n> consumer;
+
+  public LocaleSelector(SerializableConsumer<DatePickerI18n> consumer) {
+    this.consumer = consumer;
+    getContent().addValueChangeListener(ev -> updateLocale(ev.getValue()));
+    getContent().setItems(Locale.ENGLISH, Locale.GERMAN, new Locale("es"));
+    getContent().setItemLabelGenerator(locale -> locale.getDisplayLanguage(Locale.ENGLISH));
+    getContent().setLabel("Choose Language");
+    getContent().setValue(Locale.ENGLISH);
+  }
+
+  private void updateLocale(Locale locale) {
+    DatePickerI18n i18n = new DatePickerI18n();
+    DateFormatSymbols dfs = DateFormatSymbols.getInstance(locale);
+    i18n.setMonthNames(List.of(dfs.getMonths()));
+    i18n.setWeekdays(List.of(dfs.getWeekdays()).stream().skip(1).toList());
+    i18n.setWeekdaysShort(List.of(dfs.getShortWeekdays()).stream().skip(1).toList());
+
+    DayOfWeek firstDayOfWeek = WeekFields.of(locale).getFirstDayOfWeek();
+    i18n.setFirstDayOfWeek(firstDayOfWeek.getValue() % 7);
+
+    consumer.accept(i18n);
+  }
+
+}
diff --git a/src/test/java/com/flowingcode/addons/ycalendar/MonthDemo.java b/src/test/java/com/flowingcode/addons/ycalendar/MonthDemo.java
index ba0e03d..e116c57 100644
--- a/src/test/java/com/flowingcode/addons/ycalendar/MonthDemo.java
+++ b/src/test/java/com/flowingcode/addons/ycalendar/MonthDemo.java
@@ -2,7 +2,7 @@
  * #%L
  * Year Month Calendar Add-on
  * %%
- * Copyright (C) 2021 - 2023 Flowing Code
+ * Copyright (C) 2021 - 2024 Flowing Code
  * %%
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -54,8 +54,10 @@ public MonthDemo() {
       selectedDate.setText("Selected date: " + ev.getDate());
     });
 
-    Span instructions = new Span("Use arrow keys to move.");
-    add(new HorizontalLayout(instructions, selectedDate), calendar);
+    Span instructions = new Span("Use arrow keys to move."); // hide-source
+    add(new HorizontalLayout(instructions, selectedDate)); // hide-source
+    add(new LocaleSelector(calendar::setI18n)); // hide-source
+    add(calendar);
   }
 
 }
diff --git a/src/test/java/com/flowingcode/addons/ycalendar/YearDemo.java b/src/test/java/com/flowingcode/addons/ycalendar/YearDemo.java
index 3a8465d..5cee6cb 100644
--- a/src/test/java/com/flowingcode/addons/ycalendar/YearDemo.java
+++ b/src/test/java/com/flowingcode/addons/ycalendar/YearDemo.java
@@ -2,7 +2,7 @@
  * #%L
  * Year Month Calendar Add-on
  * %%
- * Copyright (C) 2021 - 2023 Flowing Code
+ * Copyright (C) 2021 - 2024 Flowing Code
  * %%
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@
 import com.vaadin.flow.component.html.Div;
 import com.vaadin.flow.component.html.Span;
 import com.vaadin.flow.component.notification.Notification;
+import com.vaadin.flow.component.orderedlayout.FlexComponent.Alignment;
 import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
 import com.vaadin.flow.component.textfield.IntegerField;
 import com.vaadin.flow.router.PageTitle;
@@ -45,6 +46,7 @@ public class YearDemo extends Div {
   public YearDemo() {
     addClassName("year-demo");
     YearCalendar calendar = new YearCalendar();
+
     calendar.setClassNameGenerator(date -> {
       if (TestUtils.isPublicHoliday(date)) {
         return "holiday";
@@ -62,6 +64,7 @@ public YearDemo() {
       selectedDate.setText("Selected date: " + ev.getDate());
     });
 
+    // #if vaadin eq 0
     Span instructions = new Span("Use arrow keys or Ctrl+arrow keys to move.");
 
     IntegerField yearField = new IntegerField();
@@ -78,9 +81,17 @@ public YearDemo() {
     }
 
     yearField.setValue(calendar.getYear());
+    yearField.setLabel("Change year");
     yearField.addValueChangeListener(e -> calendar.setYear(e.getValue()));
 
-    add(new HorizontalLayout(instructions, selectedDate), yearField, calendar);
+    LocaleSelector localeSelector = new LocaleSelector(calendar::setI18n);
+    HorizontalLayout controls = new HorizontalLayout(yearField, localeSelector);
+    controls.setSpacing(true);
+    controls.setAlignItems(Alignment.BASELINE);
+
+    add(new HorizontalLayout(instructions, selectedDate), controls);
+    // #endif
+    add(calendar);
   }
 
 }