Calendar to julian date format

1.JULIAN DATE 定义

2.示例：

定义枚举：

public enum JulianDateType
    {
        /// <summary>
        /// Julian Date (JD)
        /// </summary>
        JD,
        /// <summary>
        /// Julian Day Number (JDN)
        /// </summary>
        JDN,
        /// <summary>
        /// Chronological JD (CJD)
        /// </summary>
        CJD,
        /// <summary>
        /// Reduced JD (RJD)
        /// </summary>
        RJD,
        /// <summary>
        /// Modified JD (MJD)
        /// </summary>
        MJD,
        /// <summary>
        ///  Truncated JD (TJD)
        /// </summary>
        TJD,
        /// <summary>
        /// Dublin JD (DJD)
        /// </summary>
        DJD,
        /// <summary>
        /// Lilian Date
        /// </summary>
        LD,
        /// <summary>
        /// Military Julian Date(yddd)
        /// </summary>
        JDD,
        /// <summary>
        /// Ordinal date
        /// </summary>
        OD
    }

2.转换方法

private static Dictionary<string, int> offsetdictionary = new Dictionary<string, int>()
       {
          {"GMT-12:00",-720},{"GMT-11:00",-660},{"GMT-10:00",-600},{"GMT-09:30",-570},{"GMT-09:00",-540},{"GMT-08:00",-480},
          {"GMT-07:00",-420},{"GMT-06:00",-360},{"GMT-05:00",-300},{"GMT-04:30",-270},{"GMT-04:00",-240},{"GMT-03:30",-210},
          {"GMT-03:00",-180},{"GMT-02:00",-120},{"GMT-01:00",-60},{"GMT-00:00",0},{"GMT+01:00",60},{"GMT+02:00",120},
          {"GMT+03:00",180},{"GMT+03:30",210},{"GMT+04:00",240},{"GMT+04:30",270},{"GMT+05:00",300},{"GMT+05:30",330},
          {"GMT+05:45",345},{"GMT+06:00",360},{"GMT+06:30",390},{"GMT+07:00",420},{"GMT+08:00",480},{"GMT+09:00",540},
          {"GMT+09:30",570},{"GMT+10:00",600},{"GMT+10:30",630},{"GMT+11:00",660},{"GMT+11:30",690},{"GMT+12:00",720},
          {"GMT+12:45",765},{"GMT+13:00",780},{"GMT+14:00",840}
       };

/// <summary>
        /// Calendar to julian date format
        /// </summary>
        /// <param name="_year">year size 4</param>
        /// <param name="_month">month size 2</param>
        /// <param name="_day">day szie 2</param>
        /// <param name="_hours"> hours szie 2</param>
        /// <param name="_minutes">minutes size 2</param>
        /// <param name="_seconds">seconds size 2</param>
        /// <param name="jdtype">enum JulianDateType</param>
        /// <returns>convert julian date value</returns>
        public static string CalendarDateToJD(int _year, int _month, int _day, int _hours, int _minutes, int _seconds, JulianDateType jdtype)
        {
            string calendarstring = "";
            decimal jddate = 0;
            int dayN = 0, feb = 0;
            int cur_offset = offsetdictionary["GMT+08:00"];
            //验证是否为空
            if (((_year % 4) == 0 && (_year % 100) != 0) || (_year % 400) == 0)
            {
                // leap year
                if ((_month == 2) && (_day > 29))
                {
                    //Msg:"Leap year: February cannot have more than 29 days.
                    return "Leap year: February cannot have more than 29 days";
                }
                feb = 29;
            }
            else
            {
                // nonleap year
                if ((_month == 2) && (_day > 28))
                {
                    return "February cannot have more than 28 days.";
                }
                feb = 28;
            }

if (((_month == 4) || (_month == 6) || (_month == 9) || (_month == 11)) && (_day > 30))
            {
                return "This month cannot have more than 30 days.";
            }
            for (var i = 1; i < _month; i++)
            {
                if ((i == 4) || (i == 6) || (i == 9) || (i == 11))
                {
                    dayN += 30;
                }
                else if (i == 2)
                {
                    dayN += feb;
                }
                else
                {
                    dayN += 31;
                }
            }
            double a = 7 * (_year + (_month + 9) / 12) / 4;

double b = 3 * ((_year + (_month - 9) / 7) / 100 + 1) / 4;

double c = 275 * _month / 9;
            jddate = 367 * Convert.ToDecimal(_year) - Convert.ToDecimal(a) - Convert.ToDecimal(b) +

Convert.ToDecimal(c + _day + 1721028.5) + (Convert.ToDecimal(_hours) +

(Convert.ToDecimal(_minutes) / 60) + (Convert.ToDecimal(_seconds) / 3600) - (Convert.ToDecimal(cur_offset) / 60)) / 24;
            switch (jdtype)
            {
                case JulianDateType.JD:
                    calendarstring = Math.Round(jddate, 7).ToString();
                    break;
                case JulianDateType.JDN:
                    calendarstring = jddate.ToString().Substring(0, jddate.ToString().IndexOf("."));
                    break;
                case JulianDateType.CJD:
                    string fraction = "0." + cur_offset;
                    if (fraction.IndexOf("-") > -1) fraction = "0";
                    jddate = Math.Round(jddate, 7) + Convert.ToDecimal(0.5) + Convert.ToDecimal(fraction) * 60 / 100;
                    calendarstring = jddate.ToString();
                    break;
                case JulianDateType.RJD:
                    jddate = jddate - 2400000;
                    calendarstring = Math.Round(jddate, 7).ToString();
                    break;
                case JulianDateType.MJD:
                    jddate = jddate - Convert.ToDecimal(2400000.5);
                    calendarstring = Math.Round(jddate, 7).ToString();
                    break;
                case JulianDateType.TJD:
                    decimal intFraction = _hours * 3600 + _minutes * 60 + _seconds;
                    jddate = jddate - Convert.ToDecimal(2440000.5);
                    calendarstring = jddate.ToString().Substring(0, jddate.ToString().IndexOf(".")) + "/" + intFraction;
                    break;
                case JulianDateType.DJD:
                    calendarstring = Math.Round(jddate - 2415020, 7).ToString();
                    break;
                case JulianDateType.LD:

jddate = jddate - Convert.ToDecimal(2299160.5);
                    calendarstring = jddate.ToString().Substring(0, jddate.ToString().IndexOf("."));
                    break;
                case JulianDateType.JDD:
                    dayN += _day;
                    calendarstring = (_year.ToString() + dayN.ToString()).Substring(3);
                    break;
                case JulianDateType.OD:
                    dayN += _day;
                    calendarstring = _year.ToString() + dayN.ToString();
                    break;
            }

return calendarstring;
        }