diff --git a/include/devices.h b/include/devices.h
index 562fdad..b4dd440 100644
--- a/include/devices.h
+++ b/include/devices.h
@@ -80,7 +80,7 @@ namespace Devices {
                     if (strcmp("PRESS", msg) == 0 && !Display::tDisplaySensor.isEnabled()) {
                         Bme::data.readAll();
                         Display::tDisplaySensor.setIterations(DISPLAY_SENSOR_ITERATIONS);
-                        Display::tDisplaySensor.restart();
+                        Display::displayTask.activate(Display::tDisplaySensor);
                     };
                 }
             }).build()
@@ -89,7 +89,7 @@ namespace Devices {
             Builder<Button>::instance(new Button{"Display date", "display_date",
                 [](const char* msg) {
                     if (strcmp("PRESS", msg) == 0 && !Display::tDisplayDate.isEnabled()) {
-                        Display::tDisplayDate.restart();
+                        Display::displayTask.activate(Display::tDisplayDate);
                     };
                 }
             }).build()
@@ -98,7 +98,7 @@ namespace Devices {
             Builder<Button>::instance(new Button{"Display remaining timer", "display_remaining_timer",
                 [](const char* msg) {
                     if (strcmp("PRESS", msg) == 0 && !Display::tDisplayTimer.isEnabled()) {
-                        Display::tDisplayTimer.restart();
+                        Display::displayTask.activate(Display::tDisplayTimer);
                     }
                 }
             }).build()
diff --git a/include/display.h b/include/display.h
index 0fff91d..8457455 100644
--- a/include/display.h
+++ b/include/display.h
@@ -20,6 +20,36 @@ namespace Display {
     // Create display object
     Adafruit_7segment clockDisplay = Adafruit_7segment();
 
+    struct {
+        operator Task&() {
+            return *perm;
+        }
+
+        Task& activate(Task& task) {
+            if (temp) temp->cancel();
+            if (perm) perm->cancel();
+            if (task.getIterations() == TASK_FOREVER) {
+                task.enable();
+                perm = &task;
+            } else {
+                task.restart();
+                temp = &task;
+            }
+            return task;
+        }
+
+        void restorePerm() {
+            if (temp && temp->isEnabled()) return;  // don't enable perm when triggered by another temp on top of exsting temp
+            if (perm) perm->enable();
+        }
+
+        bool isPerm(Task& task) {
+            return perm == &task;
+        }
+    private:
+        Task *temp = nullptr, *perm = nullptr;
+    } displayTask;
+
     void displayTime();
     void displayDate();
     void displayTemp();
@@ -36,23 +66,16 @@ namespace Display {
         });
     Task tDisplaySensor(SECONDS(5), DISPLAY_SENSOR_ITERATIONS, nullptr, &ts, false,
         []() {
-            if (!tDisplayTime.isEnabled()) return false;
-            tDisplayTime.disable();
             tDisplaySensor.setCallback(displayTemp);
             return true;
         },
         []() {
             tDisplaySensor.setIterations((DISPLAY_SENSOR_ITERATIONS - 1) * 2 + 1);
-            tDisplayTime.enable();
+            displayTask.restorePerm();
         });
-    Task tDisplayDate(SECONDS(5), TASK_ONCE + 1, displayDate, &ts, false,
+    Task tDisplayDate(SECONDS(5), TASK_ONCE + 1, displayDate, &ts, false, nullptr,
         []() {
-            if (!tDisplayTime.isEnabled()) return false;
-            tDisplayTime.disable();
-            return true;
-        },
-        []() {
-            tDisplayTime.enable();
+            displayTask.restorePerm();
         });
     Task tDisplayTimer(SECONDS(10), TASK_ONCE + 1, 
         []{
@@ -60,15 +83,10 @@ namespace Display {
                 clockDisplay.print(timer, DEC);
                 clockDisplay.writeDisplay();
             }
-        }, &ts, false,
-        []{
-            if (!tDisplayTime.isEnabled()) return false;
-            tDisplayTime.disable();
-            return true;
-        },
+        }, &ts, false, nullptr,
         []{
             tDisplayTimer.setIterations(TASK_ONCE + 1);
-            tDisplayTime.enable();
+            if (!displayTask.isPerm(tDisplayTimer)) displayTask.restorePerm();
         });
     Task tTimer(MINUTES(1), TASK_FOREVER, 
         []{
@@ -76,10 +94,10 @@ namespace Display {
             timer.decrease();
             if (timer.atBeginning()) {
                 if (timer <= threshold) tDisplayTimer.setIterations(TASK_FOREVER);
-                tDisplayTimer.restart();
+                displayTask.activate(tDisplayTimer);
             } else if (timer == threshold) {
                 tDisplayTimer.setIterations(TASK_FOREVER);
-                tDisplayTimer.restart();
+                displayTask.activate(tDisplayTimer);
             }
         }, &ts, false, 
         []{
@@ -87,7 +105,7 @@ namespace Display {
             return true;
         },
         []{
-            tDisplayTimer.disable();
+            displayTask.activate(tDisplayTime);
         });
 
     struct HourFormat : public CallbackAware<callback_t> {
@@ -98,7 +116,7 @@ namespace Display {
 
         void operator=(bool value) {
             format24 = value;
-            tDisplayTime.restart();
+            if (displayTask.isPerm(tDisplayTime)) drawTime();
             if (callback) callback();
         }
     private:
@@ -225,6 +243,6 @@ namespace Display {
     void setup() {
         clockDisplay.begin(DISPLAY_ADDRESS);
         clockDisplay.setBrightness(brightness);
-        tDisplayTime.enable();
+        displayTask.activate(tDisplayTime);
     }
 }
diff --git a/src/esp_clock.cpp b/src/esp_clock.cpp
index 10ca0e9..3d800a5 100644
--- a/src/esp_clock.cpp
+++ b/src/esp_clock.cpp
@@ -31,7 +31,7 @@ Task tButton(TASK_IMMEDIATE, TASK_ONCE,
         if (Display::tDisplaySensor.isEnabled()) return;
         Bme::data.readAll();
         Display::tDisplaySensor.setIterations(DISPLAY_SENSOR_ITERATIONS);
-        Display::tDisplaySensor.restart();
+        Display::displayTask.activate(Display::tDisplaySensor);
     }, &ts);
 Task tLed(TASK_IMMEDIATE, TASK_ONCE,
     []() {
@@ -46,7 +46,7 @@ Task tReadBme(TASK_MINUTE, TASK_FOREVER, []() {
     Devices::publishBme280();
     if (abs(lastTemp - Bme::data.temp) > 0.2) {
         lastTemp = Bme::data.temp;
-        Display::tDisplaySensor.restart();
+        Display::displayTask.activate(Display::tDisplaySensor);
     }
     }, &ts);