html
<!DOCTYPE html>
<html>
<head>
<title>实时显示本地电脑时间（精确到毫秒）</title>
</head>
<body>
<h1>本地电脑时间（精确到毫秒）：</h1>
<h1 id="clock"></h1>
<script>
function updateClock() {
const now = new Date();
const year = now.getFullYear();
const month = String(now.getMonth() + 1).padStart(2, '0');
const day = String(now.getDate()).padStart(2, '0');
const hours = String(now.getHours()).padStart(2, '0');
const minutes = String(now.getMinutes()).padStart(2, '0');
const seconds = String(now.getSeconds()).padStart(2, '0');
const milliseconds = String(now.getMilliseconds()).padStart(3, '0');
const timeString = `${year}-${month}-${day} ${hours}:${minutes}:${seconds} ${milliseconds}`;
document.getElementById('clock').textContent = timeString;
}
// 每毫秒更新一次时间
setInterval(updateClock, 1);
</script>
</body>
</html>