public class ModifiedJulianDate
{ 	/*	
		
	#####################################################################	
	#                                                                   #	
	#  Please note:                                                     #
	#                                                                   #
	#  Programmed by Urs Zimmerli, Birkenhof, 8872 Weesen, Switzerland  #
	#  mail:     urs@zimmer.li                                          #
	#                                                                   #	
	#####################################################################	


	ModifiedJulianDate: Methods 	double WhatInModifiedJulian(int Year,int Month,int Day,int Hour)
						Calculates how many days elapsed since 17.11.1858
										
					int WhatInModifiedJulian(int Year,int Month,int Day)
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    	Calculates how many days elapsed since 17.11.1858
	% Note:                     %				
	%  Difference between       %	double HowManyDays(int Year1,int Month1,int Day1,int Hour1,int Year2,int Month2,int Day2,int Hour2)
	%  Julian and               %		Calculates how many days elapsed between the two mentioned days
	%  Modified Julian is       %
	%  Jul = ModJul + 2400000.5 %	int HowManyDays(int Year1,int Month1,int Day1,int Year2,int Month2,int Day2)
	%                           %           Calculates how many days elapsed since 17.11.1858
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%	
					double[] WhatInCalendar(double ModifiedJulianDate)	
						Given A ModifiedJulianDate, calculates back to true Calendary Dates:
				        	Output: Array{ Year, Month, Day, Hour}
										
					main: is just a test of the whole shit
	
	
	
	Formulas According to: 	Astronomie mit dem Personal Computer
							Oliver Montenbruck & Thomas Pfleger
							Zweite Auflage
							Springer Verlag Berlin Heidelberg 1994
							ISBN 3-540-57701-7
							Page 11 ff.									
	*/
//-----------------------------------------------------------------------------
		public double WhatInModifiedJulian(int Year, int Month, int Day, double Hour)
		{
			double A=((Year*10000)+(Month*100)+Day);
			int B;
			if (Month<3)
			{	Month=Month+12;
				Year=Year-1;
			}	
			if (A<15821004.1)
			{	B =((Year+4716)/4)-1181;
			}
			else 	
			{	B = ((int)(Year/400))-((int)(Year/100))+((int)(Year/4));
			}
			A = (365 * Year) - 679004;
			double MJD = A+B+((int)(30.6001*(Month+1)))+Day+((int)(Hour/24));
		return MJD;
		}
		
//-------------------------------------------------------------------------
		
		public int WhatInModifiedJulian(int Year, int Month, int Day)
		{double Hour = 0;
		 double MJD = WhatInModifiedJulian(Year,Month,Day,Hour);	
		 int MJDint = (int)MJD;
		return MJDint;
		}
		
//--------------------------------------------------------------------------		
		
		public double HowManyDays(int Year1, int Month1, int Day1, double Hour1,int Year2, int Month2, int Day2, double Hour2)
		{double MJD1= WhatInModifiedJulian(Year1,Month1,Day1,Hour1);
		 double MJD2= WhatInModifiedJulian(Year2,Month2,Day2,Hour2);
		 double MJDDiff = Math.abs(MJD1-MJD2);
		 return MJDDiff;
		}
		
//--------------------------------------------------------------------------
		
		public int HowManyDays(int Year1,int Month1,int Day1,int Year2,int Month2,int Day2)
		{double MJD1 = WhatInModifiedJulian(Year1,Month1,Day1);
		 double MJD2= WhatInModifiedJulian(Year2,Month2,Day2);
		 int MJDDiff =(int)Math.abs(MJD1-MJD2);
		 return MJDDiff;
		}
		
//---------------------------------------------------------------------------

		public double[] WhatInCalendar(double ModifiedJulianDate)
		{	double JD = ModifiedJulianDate + 2400000.5;		//convert to Julian		
			int JDO= (int)(JD+0.5);
			int C;
			if (JDO<2299161.0)    //check whether befor or after switch to gregorian...which introduced the whole mess
			{	C=(JDO+1524); 
			}
			else
			{	int B = (int)((JDO - 1867216.25)/36524.25);
				C =	JDO + B - ((int)(B/4)) + 1525;
			}
			int D = (int)((C - 122.1)/365.25);
			int E = (365 * D) + ((int)(D/4));
			int F = (int)((C-E)/30.6001);
			int DAY = ((int)(C-E+0.5))-((int)(30.6001*F));
			int MONTH = F-1-(12*((int)(F/14)));
			int YEAR = D - 4715 - ((int)((7+MONTH)/10));
			double HOUR = 24.0*(JD+0.5-JDO);
			
			double[] TheDate = {YEAR,MONTH,DAY,HOUR}  ;
			return TheDate;
		}
			
//-------------------------------------------------------------------------

public static void main(String[] arguments)
{	ModifiedJulianDate test = new ModifiedJulianDate();
	int Julian=test.WhatInModifiedJulian(2000,4,1);
	System.out.println(Julian);
	double[] MyDate = test.WhatInCalendar(((double)Julian));
	System.out.println(MyDate[0]); 
	System.out.println(MyDate[1]);
	System.out.println(MyDate[2]);
	System.out.println(MyDate[3]);
}


//===========================================================================
}