function updateDateTime() {
  const el = document.getElementById("datetime");
  if (!el) return;

  const now = new Date();

  const weekdays = [
    "Sonntag",
    "Montag",
    "Dienstag",
    "Mittwoch",
    "Donnerstag",
    "Freitag",
    "Samstag",
  ];

  const dayName = weekdays[now.getDay()];
  const day = String(now.getDate()).padStart(2, "0");
  const month = String(now.getMonth() + 1).padStart(2, "0");
  const year = now.getFullYear();
  const hours = String(now.getHours()).padStart(2, "0");
  const minutes = String(now.getMinutes()).padStart(2, "0");

  el.textContent = `${dayName} ${day}.${month}.${year} ${hours}:${minutes}`;
}

updateDateTime();
setInterval(updateDateTime, 1000);