Hi makenzi.exc,
Use the toLocaleString method and set the timeZone property.
Refer below example.
HTML
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <style type="text/css">
        body { font-family: Arial; font-size: 10pt; }
    </style>
</head>
<body>
    <input type="button" value="Submit" onclick="IndianDateTime()" />
    <script type="text/javascript">
        function IndianDateTime() {
            var dt = new Date(Date.UTC(2025, 02, 07, 01, 35, 25));
            alert("UTC DateTime of " + dt.toUTCString() + " is\n"
                + dt.toLocaleString("en-IN", { timeZone: 'Asia/Kolkata' }) + "IST");
        };
    </script>
</body>
</html>
 
Demo
Screenshot

 
Downloads
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