HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Time difference</title>
</head>
<body>
  <h1>Elapsed milliseconds</h1>
  <pre id="out"></pre>
  <script>
    var start = new Date("2026-01-01T00:00:00.000Z");
    var end = new Date("2026-07-01T00:00:00.000Z");
    var diffMs = end.valueOf() - start.valueOf();
    var diffDays = diffMs / (1000 * 60 * 60 * 24);
    document.getElementById("out").textContent =
      diffMs + "\n" + diffDays;
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

JavaScript Date valueOf() — time difference (Try It)