不是自己写的，做个笔记在这里，方便查找

/**
* 时间格式方法
*
* @param {any} timeStamp 时间戳，秒级/毫秒级
* @param {any} type 格式化时间类型，默认 Y-M-D H:I:S
* @returns {string} formatTime 格式化后的时间 例如： 2017-05-05 12:09:22
*/
function formatDate(timeStamp, type = 'Y-M-D H:I:S', auto = false) {
  let time = (timeStamp + '').length === 10 ? new Date(parseInt(timeStamp) * 1000) : new Date(parseInt(timeStamp));
  let _year = time.getFullYear();
  let _month = (time.getMonth() + 1) < 10 ? '0' + (time.getMonth() + 1) : (time.getMonth() + 1);
  let _date = time.getDate() < 10 ? '0' + time.getDate() : time.getDate();
  let _hours = time.getHours() < 10 ? '0' + time.getHours() : time.getHours();
  let _minutes = time.getMinutes() < 10 ? '0' + time.getMinutes() : time.getMinutes();
  let _secconds = time.getSeconds() < 10 ? '0' + time.getSeconds() : time.getSeconds();
  let formatTime = '';
  let distinctTime = new Date().getTime() - time.getTime();

  if (auto) {
    if (distinctTime <= (1 * 60 * 1000)) {
      // console.log('一分钟以内，以秒数计算');
      let _s = Math.floor((distinctTime / 1000) % 60);
      formatTime = _s + '秒前';
    } else if (distinctTime <= (1 * 3600 * 1000)) {
      // console.log('一小时以内,以分钟计算');
      let _m = Math.floor((distinctTime / (60 * 1000)) % 60);
      formatTime = _m + '分钟前';
    } else if (distinctTime <= (24 * 3600 * 1000)) {
      // console.log('一天以内，以小时计算');
      let _h = Math.floor((distinctTime / (60 * 60 * 1000)) % 24);
      formatTime = _h + '小时前';
    } else if (distinctTime <= (30 * 24 * 3600 * 1000)) {
      let _d = Math.floor((distinctTime / (24 * 60 * 60 * 1000)) % 30);
      formatTime = _d + '天前';
      // console.log('30天以内,以天数计算');
    } else {
      // 30天以外只显示年月日
      formatTime = _year + '-' + _month + '-' + _date;
    }
  } else {

switch (type) {
  case 'Y-M-D H:I:S':
    formatTime = _year + '-' + _month + '-' + _date + ' ' + _hours + ':' + _minutes + ':' + _secconds;
    break;
  case 'Y-M-D H:I:S zh':
    formatTime = _year + '年' + _month + '月' + _date + '日 ' + _hours + ':' + _minutes + ':' + _secconds;
    break;
  case 'Y-M-D H:I':
    formatTime = _year + '-' + _month + '-' + _date + ' ' + _hours + ':' + _minutes;
    break;
  case 'Y-M-D H':
    formatTime = _year + '-' + _month + '-' + _date + ' ' + _hours;
    break;
  case 'Y-M-D':
    formatTime = _year + '-' + _month + '-' + _date;
    break;
  case 'Y-M-D zh':
    formatTime = _year + '年' + _month + '月' + _date + '日';
    break;
  case 'Y-M':
    formatTime = _year + '-' + _month;
    break;
  case 'Y':
    formatTime = _year;
    break;
  case 'M':
    formatTime = _month;
    break;
   case 'D':
    formatTime = _date;
    break;
  case 'H':
    formatTime = _hours;
    break;
  case 'I':
    formatTime = _minutes;
    break;
  case 'S':
    formatTime = _secconds;
    break;
  default:
    formatTime = _year + '-' + _month + '-' + _date + ' ' + _hours + ':' + _minutes + ':' + _secconds;
    break;
  }
}
  // 返回格式化的日期字符串
  return formatTime;
}