ばーじょんｗ

<!DOCTYPE html>
<html>
<head>
    <title>Date Input</title>
</head>
<body>
    <button onclick="setToday()">今日</button>
    <button onclick="setLastWeek()">1週間前</button><br><br>
    Starttime: <input type="text" id="starttime"><br>
    Endtime: <input type="text" id="endtime">
    <script>
        function setToday() {
            let today = new Date();
            let month = (today.getMonth() + 1).toString().padStart(2, '0');
            let date = today.getDate().toString().padStart(2, '0');
            document.getElementById('starttime').value = today.getFullYear() + '/' + month + '/' + date + ' 00:00';
            document.getElementById('endtime').value = today.getFullYear() + '/' + month + '/' + date + ' 23:59';
        }
        function setLastWeek() {
            let lastWeek = new Date();
            lastWeek.setDate(lastWeek.getDate() - 7);
            let month = (lastWeek.getMonth() + 1).toString().padStart(2, '0');
            let date = lastWeek.getDate().toString().padStart(2, '0');
            document.getElementById('starttime').value = lastWeek.getFullYear() + '/' + month + '/' + date + ' 00:00';
            
            let today = new Date();
            month = (today.getMonth() + 1).toString().padStart(2, '0');
            date = today.getDate().toString().padStart(2, '0');
            document.getElementById('endtime').value = today.getFullYear() + '/' + month + '/' + date + ' 23:59';
        }
    </script>
</body>
</html>