diff --git a/index.html b/index.html
index 89086d3..14d8515 100644
--- a/index.html
+++ b/index.html
@@ -57,6 +57,11 @@ <h3>Settings</h3>
         <input type="checkbox" id="play-sound" name="play-sound"/>
       </div>
 
+      <label for="overtime">Display overtime :</label>
+      <div>
+        <input type="checkbox" id="overtime" name="overtime"/>
+      </div>
+
       <label for="orientation">Orientation :</label>
       <div>
         <select id="orientation" name="orientation" disabled>
diff --git a/js/app.mjs b/js/app.mjs
index 4122ff5..af0b80a 100644
--- a/js/app.mjs
+++ b/js/app.mjs
@@ -17,7 +17,7 @@ const totalHeight = window.innerHeight;
 let elapsed = 0;
 let pause = true;
 const pauseChar = '⏸️';
-const playChar = '▶️'; 
+const playChar = '▶️';
 
 let wakeLock = null;
 
@@ -68,15 +68,19 @@ function startAnimation(startTime = performance.now(), settings) {
     } else if (progress < 1) {
       requestAnimationFrame(animate);
     } else {
-      timer.textContent = "00:00";
-      playBeep(settings);
-      timer.classList.add("blinking"); // démarre le clignotement
-
-      // Arrête le clignotement après 5 secondes
-      setTimeout(() => {
-        timer.classList.remove("blinking");
-        timer.style.opacity = "1";
-      }, 5000);
+      if (settings.overtime) {
+        requestAnimationFrame(animate);
+      } else {
+        timer.textContent = "00:00";
+        playBeep(settings);
+        timer.classList.add("blinking"); // démarre le clignotement
+
+        // Arrête le clignotement après 5 secondes
+        setTimeout(() => {
+          timer.classList.remove("blinking");
+          timer.style.opacity = "1";
+        }, 5000);
+      }
     }
   }
   requestAnimationFrame(animate);
@@ -132,8 +136,7 @@ function applySettings(settings, timer) {
 export function init() {
   const settings = initSettings({
     durationInSeconds: parseDuration(params.get("duration")), soundEnabled: params.get("sound") === "true", settingsModalElement: settingsModal, settingsFormElement: settingsForm
-  })
-
+  });
   // Wakelock: réactiver si la page revient au premier plan
   document.addEventListener('visibilitychange', () => {
     if (wakeLock !== null && document.visibilityState === 'visible') {
@@ -145,7 +148,7 @@ export function init() {
   closeSettingsBtn.addEventListener('click', hideSettings);
   resetBtn.addEventListener('click', resetDefaultSettings);
   submitBtn.addEventListener('click', () => {
-    submitSettings()
+    submitSettings(settingsForm)
     applySettings(settings, timer);
   });
   startBtn.addEventListener('click', () => switchPause(settings));
diff --git a/js/settings.mjs b/js/settings.mjs
index 7e11d16..830cade 100644
--- a/js/settings.mjs
+++ b/js/settings.mjs
@@ -6,17 +6,22 @@ const defaultSettings = {
     secondThreshold: 0.9,
     thirdThreshold: 0.95,
     soundEnabled: false,
-    orientation: "upward"
+    orientation: "upward",
+    overtime: true,
 }
 
 let settings;
 let settingsModal;
-let settingsForm;
 
-function initSettings({ durationInSeconds, soundEnabled, settingsModalElement, settingsFormElement }) {
+function initSettings({
+    durationInSeconds = defaultSettings.durationInSeconds,
+    soundEnabled = defaultSettings.soundEnabled,
+    settingsModalElement,
+    settingsFormElement,
+}) {
     settingsModal = settingsModalElement;
-    settingsForm = settingsFormElement;
     settings = { ...defaultSettings, durationInSeconds, soundEnabled }
+    updateSettingsForm(settingsFormElement);
     return settings;
 }
 
@@ -28,7 +33,7 @@ function hideSettings() {
     settingsModal.close();
 }
 
-function submitSettings() {
+function submitSettings(settingsForm) {
     settings.durationInSeconds = Number(settingsForm["durationMinutes"].value * 60) + Number(settingsForm["durationSeconds"].value)
     settings.colorScheme = settingsForm["color-scheme"].value;
     settings.showTimer = settingsForm["show-timer"].checked;
@@ -37,12 +42,13 @@ function submitSettings() {
     settings.thirdThreshold = settingsForm["threshold3"].value / 100;
     settings.soundEnabled = settingsForm["play-sound"].checked;
     settings.orientation = settingsForm["orientation"].value;
+    settings.overtime = settingsForm["overtime"].checked;
 
     hideSettings();
 }
 
 
-function updateSettingsForm() {
+function updateSettingsForm(settingsForm) {
     // Apply the settings to the form so it reflects current settings
     settingsForm["durationMinutes"].value = Math.floor(settings.durationInSeconds / 60);
     settingsForm["durationSeconds"].value = settings.durationInSeconds % 60;
@@ -53,6 +59,7 @@ function updateSettingsForm() {
     settingsForm["threshold3"].value = settings.thirdThreshold * 100;
     settingsForm["play-sound"].checked = settings.soundEnabled;
     settingsForm["orientation"].value = settings.orientation;
+    settingsForm["overtime"].checked = settings.overtime;
 }
 
 function resetDefaultSettings() {
diff --git a/js/tests/settings.test.js b/js/tests/settings.test.js
index f7de088..73c75a6 100644
--- a/js/tests/settings.test.js
+++ b/js/tests/settings.test.js
@@ -2,10 +2,22 @@ import { describe, it, mock } from "node:test";
 import assert from "node:assert";
 import { initSettings, showSettings, hideSettings, submitSettings, updateSettingsForm } from "../settings.mjs";
 
+const settingsFormElementEmpty = {
+    ["color-scheme"]: { value: undefined },
+    ["threshold1"]: { value: undefined },
+    ["threshold2"]: { value: undefined },
+    ["threshold3"]: { value: undefined },
+    durationMinutes: { value: undefined },
+    durationSeconds: { value: undefined },
+    orientation: { value: undefined },
+    ["show-timer"]: { checked: undefined },
+    ["play-sound"]: { checked: undefined },
+    overtime: { checked: undefined },
+};
 
 describe('initSettings', () => {
     it(`Should create settings with given parameters`, () => {
-        const settings = initSettings({ durationInSeconds: 20, soundEnabled: true });
+        const settings = initSettings({ durationInSeconds: 20, soundEnabled: true, settingsFormElement: { ...settingsFormElementEmpty } });
 
         assert.deepEqual(settings, {
             colorScheme: 'zenika-colors',
@@ -16,6 +28,7 @@ describe('initSettings', () => {
             showTimer: true,
             soundEnabled: true,
             thirdThreshold: 0.95,
+            overtime: true,
         });
     });
 });
@@ -24,7 +37,7 @@ describe('initSettings', () => {
 describe('showSettings', () => {
     it(`Should open the modal`, () => {
         const settingsModalElement = { showModal: mock.fn(), close: mock.fn() };
-        initSettings({ settingsModalElement });
+        initSettings({ settingsModalElement, settingsFormElement: { ...settingsFormElementEmpty } });
 
         showSettings();
 
@@ -36,7 +49,7 @@ describe('showSettings', () => {
 describe('hideSettings', () => {
     it(`Should close the modal`, () => {
         const settingsModalElement = { showModal: mock.fn(), close: mock.fn() };
-        initSettings({ settingsModalElement });
+        initSettings({ settingsModalElement, settingsFormElement: { ...settingsFormElementEmpty } });
 
         hideSettings();
 
@@ -57,22 +70,23 @@ describe('submitSettings', () => {
         orientation: { value: 'downward' },
         ["show-timer"]: { checked: false },
         ["play-sound"]: { checked: false },
+        overtime: { checked: false },
     };
 
     it(`Should close the modal`, () => {
         const settingsModalElement = { showModal: mock.fn(), close: mock.fn() };
-        initSettings({ settingsModalElement, settingsFormElement });
+        initSettings({ settingsModalElement, settingsFormElement: { ...settingsFormElementEmpty } });
 
-        submitSettings();
+        submitSettings(settingsFormElement);
 
         assert.equal(settingsModalElement.close.mock.callCount(), 1);
     });
 
     it(`Should update the settings with the given form`, () => {
         const settingsModalElement = { showModal: mock.fn(), close: mock.fn() };
-        const settings = initSettings({ settingsModalElement, settingsFormElement });
+        const settings = initSettings({ durationInSeconds: 61, settingsModalElement, settingsFormElement: { ...settingsFormElementEmpty } });
 
-        submitSettings();
+        submitSettings(settingsFormElement);
 
         assert.deepEqual(settings, {
             colorScheme: 'zenika-other-colors',
@@ -83,29 +97,19 @@ describe('submitSettings', () => {
             orientation: 'downward',
             showTimer: false,
             soundEnabled: false,
+            overtime: false,
         });
     });
 });
 
 
 describe('updateSettingsForm', () => {
-    const settingsFormElement = {
-        ["color-scheme"]: { value: undefined },
-        ["threshold1"]: { value: undefined },
-        ["threshold2"]: { value: undefined },
-        ["threshold3"]: { value: undefined },
-        durationMinutes: { value: undefined },
-        durationSeconds: { value: undefined },
-        orientation: { value: undefined },
-        ["show-timer"]: { checked: undefined },
-        ["play-sound"]: { checked: undefined },
-    };
-
     it(`Should update the form with the given settings`, () => {
         const settingsModalElement = { showModal: mock.fn(), close: mock.fn() };
+        const settingsFormElement = { ...settingsFormElementEmpty };
         initSettings({ settingsModalElement, settingsFormElement, soundEnabled: true, durationInSeconds: 123 });
 
-        updateSettingsForm();
+        updateSettingsForm(settingsFormElement);
 
         assert.deepEqual(settingsFormElement, {
             ["color-scheme"]: { value: 'zenika-colors' },
@@ -117,6 +121,7 @@ describe('updateSettingsForm', () => {
             orientation: { value: 'upward' },
             ["show-timer"]: { checked: true },
             ["play-sound"]: { checked: true },
+            overtime: { checked: true },
         });
     });
 });
diff --git a/js/tests/utils.test.js b/js/tests/utils.test.js
index d15d9f7..0c1fb7f 100644
--- a/js/tests/utils.test.js
+++ b/js/tests/utils.test.js
@@ -3,16 +3,31 @@ import assert from "node:assert";
 import { updateTimer, updateBackground, parseDuration } from "../utils.mjs";
 
 describe('Update timer', () => {
-  [
-    { timer: '00:00', time: 0 },
-    { timer: '00:02', time: 2 },
-    { timer: '01:01', time: 61 },
-    { timer: '1440:01', time: 86401 }
-  ].forEach(({ timer, time }) => {
-    it(`with ${time} displays ${timer}`, () => {
-      assert.equal(updateTimer(time), timer);
-    })
-  })
+  describe('When remaining time is greater than 0', () => {
+    [
+      { timer: '00:00', time: 0 },
+      { timer: '00:02', time: 2 },
+      { timer: '01:01', time: 61 },
+      { timer: '1440:01', time: 86401 }
+    ].forEach(({ timer, time }) => {
+      it(`with ${time} displays ${timer}`, () => {
+        assert.equal(updateTimer(time), timer);
+      })
+    });
+  });
+
+  describe('When remaining time is less than 0', () => {
+    [
+      { timer: '00:00', time: -0 },
+      { timer: '+00:02', time: -2 },
+      { timer: '+01:01', time: -61 },
+      { timer: '+1440:01', time: -86401 }
+    ].forEach(({ timer, time }) => {
+      it(`with ${time} displays ${timer}`, () => {
+        assert.equal(updateTimer(time), timer);
+      })
+    });
+  });
 });
 
 describe('updateBackground', () => {
diff --git a/js/utils.mjs b/js/utils.mjs
index e5b9ed1..5d479a8 100644
--- a/js/utils.mjs
+++ b/js/utils.mjs
@@ -1,9 +1,9 @@
 export function updateTimer(secRemaining) {
-  const sec = Math.max(0, Math.ceil(secRemaining));
+  const sec = Math.abs(Math.ceil(secRemaining));
   const minutes = Math.floor(sec / 60);
   const remainingSeconds = sec % 60;
   // format into "mm:ss" padded with 0 if needed
-  return `${String(minutes).padStart(2, '0')}:${String(remainingSeconds).padStart(2, '0')}`;
+  return `${secRemaining < 0 ? '+' : ''}${String(minutes).padStart(2, '0')}:${String(remainingSeconds).padStart(2, '0')}`;
 }
 
 export function updateBackground({ background, totalHeight, progress, settings }) {