code: function(year, month, day) {
  			var date = this._validate(year, month, day, $.calendars.local.invalidDate);
  			year = date.year();
  			month = date.month();
  			day = date.day();
  			var epBase = year - (year >= 0 ? 474 : 473);
  			var epYear = 474 + mod(epBase, 2820);
  			return day + (month <= 7 ? (month - 1) * 31 : (month - 1) * 30 + 6) +
  				Math.floor((epYear * 682 - 110) / 2816) + (epYear - 1) * 365 +
  				Math.floor(epBase / 2820) * 1029983 + this.jdEpoch - 1;
  		}
docs: Retrieve the Julian date equivalent for this date,
  i.e. days since January 1, 4713 BCE Greenwich noon.
  @memberof PersianCalendar
  @param year {CDate|number} The date to convert or the year to convert.
  @param [month] {number} The month to convert.
  @param [day] {number} The day to convert.
  @return {number} The equivalent Julian date.
  @throws Error if an invalid date or a different calendar used.