限制在CakePHP输入表单中选择早于今天的日期

echo $this->Form->create();
echo $this->Form->date('selected_date', ['minYear' => date('Y')]);
echo $this->Form->button('Submit');
echo $this->Form->end();

public function submitForm() {
    $this->request->allowMethod(['post']);

    $data = $this->request->getData();
    $selectedDate = $data['selected_date'];

    // 进行表单验证，确保选择的日期早于今天
    $validator = new Validator();
    $validator->add('selected_date', 'custom', [
        'rule' => function ($value, $context) {
            $selectedDate = strtotime($value);
            $today = strtotime(date('Y-m-d'));
            return $selectedDate < $today;
        },
        'message' => '请选择早于今天的日期'
    ]);

    $errors = $validator->errors($data);
    if (empty($errors)) {
        // 表单验证通过，继续处理其他逻辑
        // ...
    } else {
        // 表单验证失败，显示错误信息
        $this->set('errors', $errors);
        $this->render('form');
    }
}