RDS 年月日换算

        /// 从儒略日转换为年月日(如把54863转换为2009-02-01)
        /// </summary>
        /// <param name="mjdstr">简化儒略日</param>
        /// <returns>年-月-日</returns>
#if 1
void GetDateTimeByMJD(u32_t mjdstr)
{
            //把简化儒略日转换为儒略日(MJD TO JD)
            double xdata JD = (double)(mjdstr) + 2400000.5;
            double xdata Z = floor(JD + 0.5);
            double xdata W = floor((Z - 1867216.25) / 36524.25);
            double xdata X = floor(W / 4);
            double xdata AA = floor(Z + 1 + W - X);
            double xdata BB = floor(AA + 1524);
            double xdata CC = floor((BB - 122.1) / 365.25);
            double xdata DD = floor(365.25 * CC);
            double xdata EE = floor((BB - DD) / 30.6001);
            double xdata FF = floor(30.6001 * EE);
            date.Day = BB - DD - FF;
//            double Month;
//            double Year;
            if ((EE - 13) <= 12 && (EE - 13) > 0)
                date.Month = EE - 13;
            else
                date.Month = EE - 1;
            if (date.Month == 1 || date.Month == 2)
                date.Year = CC - 4715;
            else
                date.Year = CC - 4716;

}

  /// 从日期获得儒略日
        /// </summary>
        /// <param name="dt">时间</param>
        /// <returns>简化儒略日mjd</returns>
u32_t GetMJd(T_DATA dt)
{
 long I = dt.Year, J = dt.Month, K = dt.Day;
 //求出给定年(I)，月(J)，日(K)的儒略日:
 double jd = K - 32075 + 1461 * (I + 4800 + (J - 14) / 12) / 4 + 367 * (J - 2 - (J - 14) / 12 * 12) / 12 - 3 * ((I + 4900 + (J - 14) / 12) / 100) / 4;
 u32_t mjdStr = (jd - 2400000.5);
 return    mjdStr;
// int x = mjdStr.IndexOf(".");
// if (x == -1)
// {
//     return long.Parse(mjdStr);
// }
// else
// {
//     mjdStr = mjdStr.Substring(0, x);
//     return long.Parse(mjdStr);
// }
}