Javascript Check if date is in the Past

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Check if Date is Today</title>
    <script>
        function isDateToday(dateToCheck) {
            var currentDate = new Date();
            var isToday = dateToCheck.getFullYear() === currentDate.getFullYear() &&
                dateToCheck.getMonth() === currentDate.getMonth() &&
                dateToCheck.getDate() === currentDate.getDate();

return isToday;
        }
        function checkDate() {
            var dateString = document.getElementById('dateInput').value;
            var dateToCheck = new Date(dateString); // Creates a date object from the input
            if (isDateToday(dateToCheck)) {
                alert('The date is today.');
            } else {
                alert('The date is not today.');
            }
        }
    </script>
</head>
<body>
    <h2>Javascript Check if Date is Today</h2>
    <label for="dateInput">Enter a Date:</label>
    <input type="date" id="dateInput">
    <button onclick="checkDate()">Check</button>
</body>

</html>