JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    		<thead>			
			<tr>
				<th>&nbsp;</th>
				
				<th colspan="31">May</th>				
				
				<th colspan="30">June</th>				
				
				<th colspan="31">July</th>				
				
				<th colspan="31">August</th>				
				
				<th...

CSS

table {width: auto; display: block; padding-left: 100px; display: block; height: 100px; overflow: auto; padding-top: 50px}

table tr td:first-child {position: fixed; width: 100px; margin-left: -100px}

tbody { display: block; }

thead {position: absolute; height: 50px; margin-top: -50px}