diff --git a/include/display.h b/include/display.h
index a560284..8b660b8 100644
--- a/include/display.h
+++ b/include/display.h
@@ -23,6 +23,10 @@ namespace Display {
   int currentHour = -1;
   int currentMin = -1;
   bool hourFormat24 = false;
+  void (*hourFormatChangedCallback)(bool format24);
+  void onHourFormatChanged(void (*f)(bool)) {
+    hourFormatChangedCallback = f;
+  }
 
   // Create display object
   Adafruit_7segment clockDisplay = Adafruit_7segment();
@@ -121,6 +125,12 @@ namespace Display {
     tDisplay.enableDelayed(DISPLAY_TIME);
   }
 
+  void changeHourFormat24(bool format24) {
+    hourFormat24 = format24;
+    drawTime();
+    hourFormatChangedCallback(format24);
+  }
+
   void setup() {
     clockDisplay.begin(DISPLAY_ADDRESS);
     clockDisplay.setBrightness(Brightness::current);
diff --git a/include/mqtt.h b/include/mqtt.h
index 085d196..5d7d229 100644
--- a/include/mqtt.h
+++ b/include/mqtt.h
@@ -66,6 +66,12 @@ namespace Mqtt {
                 Display::Brightness::set(String{ msg }.toInt());
             }
         })->withStateTopic();
+    
+    Ha::Command* hourFormatMqtt = (new Ha::Switch{"ESP Clock Format 24h", "format_24h",
+            [](const char* msg) {
+                String{ "ON" }.equals(msg) ? Display::changeHourFormat24(true) : Display::changeHourFormat24(false);
+            }
+        })->withStateTopic();
 
     Ha::Command* switches[] = {
         new Ha::Button{"ESP Clock Restart", "restart",
@@ -74,17 +80,7 @@ namespace Mqtt {
             }
         },
         ledMqtt,
-        new Ha::Switch{"ESP Clock Format 24h", "format_24h",
-            [](const char* msg) {
-                if (String{ "ON" }.equals(msg)) {
-                    Display::hourFormat24 = true;
-                    Display::drawTime();
-                } else {
-                    Display::hourFormat24 = false;
-                    Display::drawTime();
-                }
-            }
-        },
+        hourFormatMqtt,
         brightnessMqtt
     };
 
@@ -103,7 +99,7 @@ namespace Mqtt {
     }
 
     void publishBrightness() {
-        if (!client.connected()) return ;
+        if (!client.connected()) return;
         char message[32];
         sprintf(message, "%u", Display::Brightness::current);
         publish(brightnessMqtt->stateTopic, message);
@@ -157,6 +153,9 @@ namespace Mqtt {
 
     void setup() {
         Display::Brightness::onChanged(publishBrightness);
+        Display::onHourFormatChanged([](bool format24) {
+            if (client.connected()) publish(hourFormatMqtt->stateTopic, format24 ? "ON" : "OFF");
+        });
         client.onConnect([](bool sessionPresent) {
             tPublishConfig.enable();
             tPublishBmp.enableIfNot();