时区的计算方法：

计算的区时 = 已知区时 － (已知区时的时区 - 要计算区时的时区)
注：东时区为正，西时区为负

  1. function dateFormatByTimezone(date = new Date(), data_timezone = 8, target_timezone = 8) {
  2.     let msec = new Date(date).getTime() - (data_timezone - target_timezone) * 60 * 60 * 1000;
  3.     date = new Date(msec);
  4.       let supNum = function(n) {
  5.             return n < 10 ? '0' + n : n;
  6.         }
  7.     return `${
  8.         date.getFullYear()
  9.         }-${
  10.         supNum(date.getMonth()+1)
  11.         }-${
  12.             supNum(date.getDate())
  13.         } ${
  14.         supNum(date.getHours())
  15.     }:${
  16.       supNum(date.getMinutes())
  17.     }:${
  18.         supNum(date.getSeconds())
  19.     }`;
  20. }