html实时时间代码格式为年月日 时：分：秒：

<!DOCTYPE html>
<html>
<head>
	<title>实时时间</title>
	<script type="text/javascript">
		function showTime() {
			var date = new Date();
			var year = date.getFullYear();
			var month = date.getMonth() + 1;
			var day = date.getDate();
			var hour = date.getHours();
			var minute = date.getMinutes();
			var second = date.getSeconds();
			if (month < 10) {
				month = "0" + month;
			}
			if (day < 10) {
				day = "0" + day;
			}
			if (hour < 10) {
				hour = "0" + hour;
			}
			if (minute < 10) {
				minute = "0" + minute;
			}
			if (second < 10) {
				second = "0" + second;
			}
			var time = year + "." + month + "." + day + " " + hour + ":" + minute + ":" + second;
			document.getElementById("time").innerHTML = time;
		}
		setInterval(showTime, 1000);
	</script>
</head>
<body>
	<p id="time"></p>
</body>
</html>