index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>FE1010</title>
</head>
<body>
    <style>
        th,td{
            border-color:black;
            border-width: 1px;
            border-style: solid;
            padding: 10px 5px;
            text-align:left;
        }
        table{
            border-collapse: collapse;
        }
    </style>
    <table>
        <thead>
            <th>Ngày</th>
            <th>Thời gian bắt đầu</th>
            <th>Thời gian kết thúc</th>
        </thead>
        <tbody>
            <tr>
                <td class="day1"></td>
                <td class="time-start1"></td>
                <td class="time-finish1"></td>
            </tr>
            <tr>
                <td class="day2"></td>
                <td class="time-start2"></td>
                <td class="time-finish2"></td>
            </tr>
        </tbody>
    </table>
    <script src="index.js"></script>
</body>
</html>