diff --git a/2621.sleep.js b/2621.sleep.js
new file mode 100644
index 0000000..e2bc74b
--- /dev/null
+++ b/2621.sleep.js
@@ -0,0 +1,18 @@
+/**
+ * URL of this problem
+ * https://leetcode.com/problems/sleep/
+ */
+
+/**
+ * @param {number} millis
+ */
+async function sleep(millis) {
+	await new Promise((resolve) => {
+		setTimeout(resolve, millis);
+	});
+}
+
+/**
+ * let t = Date.now()
+ * sleep(100).then(() => console.log(Date.now() - t)) // 100
+ */