标准时间转换

  function timeChange (dateStr) {
      let endDate,
          date = new Date(dateStr);
      endDate = date.getFullYear() + '-' 
              + (date.getMonth() + 1) + '-' 
              + date.getDate() + ' ' 
              + date.getHours() + ':' 
              + date.getMinutes() + ':'
              + date.getSeconds(); 
      return endDate;
  }
  timeChange(Thu Dec 14 2017 11:50:34 GMT+0800 (中国标准时间); 
  =>2017-12-1 11:50:34