use the new timestamp endpoint for tests

src/components/overview.tsx

@@ -1,14 +1,20 @@
-import React, { useState } from 'react';
+import React, { useEffect, useState } from 'react';
 import axios from 'axios';
 
 export const Overview: React.FC = () => {
   const [msg, setMsg] = useState('LOADING');
 
-  axios.get('http://localhost:3000/auth/user', {
+  useEffect(() => {
+    const interval = setInterval(() => {
+      axios.get('http://localhost:3000/system/timestamp', {
         headers: {
           Authorization: `Bearer ${sessionStorage.getItem('token')}`,
-    },
-  }).then((data) => setMsg(data.data)).catch(() => setMsg('FAILED'));
+        }
+      }).then((response) => setMsg(new Date(response.data).toISOString()));
+    }, 5000);
+
+    return () => clearInterval(interval);
+  }, []);
 
   return <>OVERVIEW {msg}</>;
 };