JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html> 
<html>
	<head>
		<meta charset="utf-8">
		
		<script>
			function displayCalender()
			{
			 var t = new Date();
			 var y = t.getFullYear();
			 var m = t.getMonth() + 1;
			 var d1 = t.getDate();
			 var d2 = t.getDay();

			 var s = '<h2 align="center">' + y + '年' + m + '月</h2>';
			 s += '<h1 align="center">' + d1 + '</h1>';
			 s += '<h3 align="center">星期' + d2 + '</h3>';
			 document.getElementById("showCalender").innerHTML = s;
			}
		</script>
	</head>
	<body>
		<div id="showCalender"></div>
		<script>displayCalender()</script>
	</body>
</html>