如何根据包含的时间属性将副标题添加到div？

<div data-time="2022-01-01">内容</div>

var divElements = document.querySelectorAll('div[data-time]');
divElements.forEach(function(element) {
  var time = element.getAttribute('data-time');
  var subtitle = generateSubtitle(time); // 根据时间生成副标题的自定义函数
  element.innerHTML += '<h2>' + subtitle + '</h2>';
});

function generateSubtitle(time) {
  var date = new Date(time);
  var year = date.getFullYear();
  var month = date.getMonth() + 1;
  var day = date.getDate();
  return year + '年' + month + '月' + day + '日';
}