bk04ch08/example10.html

<!doctype html>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <title>Extracting the day name from a date</title>
        <style>
            body {
                margin: 1em;
                font-size: 1.5em;
            }
            div {
                margin-top: .5em;
            }
        </style>
    </head>
    <body>
        <div id="output">
        </div>

        <script>
            const dateNow = new Date();
            document.getElementById("output").innerHTML = `The date is ${dateNow}<br>The day name is ${dateNow.toLocaleDateString('default', { weekday: 'long' })}`;
        </script>
    </body>
</html>