text: (function () {
  
      var root = this,
          T = (root.T = {});
  
      var ratio = 1 / Math.PI / 2 * 365 * 24 * 3600;
  
      var atime = 0;//Astronical time
      T.elapse = function (dt) {
          atime = atime + dt / ratio;
          return {
              tao: dt / ratio,
              dt:  dt,
              dld: dt / 3600 / 30,
              time: T.time(),
              year: T.year(),
              lday: T.lday(),
              lyear: T.lyear()
          };
      };
  
      //various time
      T.time = function () {
          return atime * ratio;
      };
      T.year = function () {
          return atime / Math.PI / 2;
      };
      T.lday = function () {
          return atime * ratio / 3600 / 30;
      };
      T.lyear = function () {
          return atime * ratio / 3600 / 30 / 500;
      };
  
  
  })();
  