diff --git a/src/pages/countdown/index.astro b/src/pages/countdown/index.astro
index 03713d7..33d7ce9 100644
--- a/src/pages/countdown/index.astro
+++ b/src/pages/countdown/index.astro
@@ -15,21 +15,22 @@ import Layout from '../../layouts/Layout.astro';---
 
   const queryString = window.location.search
   const urlParams =  new URLSearchParams(queryString);
+
   const titleParam = urlParams.get("title");
-  const datetimeParam = urlParams.get("datetime");
+  const datetimeParam = urlParams.get("datetime") ?? "";
 
   titleElement.innerText = titleParam;
   const date = new Date(datetimeParam)
 
   const interval = setInterval(() => {
     const now = new Date()
-    const diff = Math.abs(date.getTime() - now.getTime());
+    const diff = Math.floor(Math.abs(date.getTime() - now.getTime()) / 1000);
     if (diff <= 0) clearInterval(interval);
 
-    const days = Math.floor(diff / (1000 * 3600 * 24))
-    const hours = Math.floor(diff / (1000 * 3600)) % 24
-    const minutes = Math.floor(diff / (1000 * 60)) % 60
-    const seconds = Math.floor(diff / (1000)) % 60
+    const days = Math.floor(diff / 86400)
+    const hours = Math.floor(diff / 3600) % 24
+    const minutes = Math.floor(diff / 600) % 60
+    const seconds = Math.floor(diff) % 60
 
     const display = []
     if (days > 0) display.push(`${days}d`)