code: function(dateString) {
          var match = dateString.match(DATE_REGEXP);
  
          var year = this._validateYear(+match[1]);
  
          var month = +match[2];
          var isIntercalary = !!match[3];
          var monthIndex = this.toMonthIndex(year, month, isIntercalary);
  
          var day = +match[4];
  
          return this.newDate(year, monthIndex, day);
      }
docs: Create a new date from a string.
  @memberof ChineseCalendar
  @param dateString {string} String representing a Chinese date
  @return {CDate} The new date.
  @throws Error if an invalid date.