diff --git a/Sprint-3/alarmclock/alarmclock.js b/Sprint-3/alarmclock/alarmclock.js
index 6ca81cd3b..9f2f24c32 100644
--- a/Sprint-3/alarmclock/alarmclock.js
+++ b/Sprint-3/alarmclock/alarmclock.js
@@ -1,4 +1,46 @@
-function setAlarm() {}
+const heading = document.getElementById("timeRemaining");
+const input = document.getElementById("alarmSet");
+const setBtn = document.getElementById("set");
+
+let remaining = 0;
+let intervalId = null;
+
+function format(seconds) {
+ const minute = String(Math.floor(seconds / 60)).padStart(2, "0");
+ const second = String(seconds % 60).padStart(2, "0");
+ return `${m}:${s}`;
+}
+
+function updateHeading() {
+ heading.textContent = `Time Remaining: ${format(remaining)}`;
+}
+
+function tick() {
+ if (remaining <= 0) {
+ clearInterval(intervalId);
+ intervalId = null;
+ updateHeading();
+ if (typeof window.playAlarm === "function") {
+ window.playAlarm();
+ }
+ return;
+ }
+ remaining -= 1;
+ updateHeading();
+}
+
+function setAlarm() {
+ const value = parseInt(input.value, 10);
+ // Guard clause: ignore invalid or non-positive input
+ if (!Number.isFinite(value) || value <= 0) return;
+ if (intervalId) clearInterval(intervalId);
+ remaining = value;
+ updateHeading();
+ intervalId = setInterval(tick, 1000);
+}
+
+setBtn.addEventListener("click", setAlarm);
+updateHeading();
// DO NOT EDIT BELOW HERE
diff --git a/Sprint-3/alarmclock/index.html b/Sprint-3/alarmclock/index.html
index 48e2e80d9..ff2d3b453 100644
--- a/Sprint-3/alarmclock/index.html
+++ b/Sprint-3/alarmclock/index.html
@@ -4,7 +4,7 @@
- Title here
+ Alarm clock app