[JAVA] WTF IS UP WITH DATES AND GREGORIAN CALENDAR ON SEP 1, 1905?

private static DatatypeFactory dataFactory = null;
	static {
		try {
			dataFactory = DatatypeFactory.newInstance();
		} catch (DatatypeConfigurationException e) {
			throw new IllegalStateException(
					"Error while trying to obtain a new instance of DatatypeFactory",
					e);
		}
	}

	protected static String LONG_DATE_PATTERN = "yyyy-MM-dd HH:mm:ss";
	protected static String SHORT_DATE_PATTERN = "yyyy-MM-dd";
		
	public static void main(String[] args) throws IOException {

		SimpleMain sm = new SimpleMain();
		// TODO Auto-generated method stub
		System.out.println("Hello World!");
		sm.datestuff();
	}


	private void datestuff() {
		Date myDate = new Date(1,0,1,0,0,0);
		Date my1Sep1905 = new Date(5,8,1,0,0,0);
		Date my31Aug1905 = new Date(5,7,31,0,0,0);
		Date my1997 = new Date(97,0,1,0,0,0);
		System.out.println("MD:" + myDate);
		System.out.println("MDSep1905:" + my1Sep1905);
		System.out.println("MDAug31:" + my31Aug1905);
		System.out.println("MD97:" + my1997);
		System.out.println("^^^^ INIT ^^^^^--------------------------");
		System.out.println("vvvv Business Effective Date vvvvvvvv--------------------------");
		XMLGregorianCalendar businessEffectiveDate = convertDateToXMLGregorianCalendar(myDate);
		XMLGregorianCalendar bed31Aug1905 = convertDateToXMLGregorianCalendar(my31Aug1905);
		XMLGregorianCalendar bed1905 = convertDateToXMLGregorianCalendar(my1Sep1905);
		XMLGregorianCalendar bed97 = convertDateToXMLGregorianCalendar(my1997);
		System.out.println("BED:" + businessEffectiveDate);
		System.out.println("BED1Sep1905:" + bed1905);
		System.out.println("BED31Aug1905:" + bed31Aug1905);
		System.out.println("BED97:" + bed97);
		
		String myString = businessEffectiveDate.toString();
		System.out.println("myStr:" + myString);
		

		System.out.println("--------------------------------");
		Calendar myCal = Calendar.getInstance();
	
		System.out.println("myCal: " + myCal);
		Date newD = businessEffectiveDate.toGregorianCalendar().getTime();
		System.out.println("newDate from myDate:" + newD);
		Date newD2 = bed1905.toGregorianCalendar().getTime();
		System.out.println("newDate2 from 1Sep1905:" + newD2);
		Date newD3 = bed31Aug1905.toGregorianCalendar().getTime();
		System.out.println("newDate3 from 31Aug1905:" + newD3);
		Date newD4 = bed97.toGregorianCalendar().getTime();
		System.out.println("newDate4 from 1997:" + newD4);
		
		System.out.println("--------------------------------millis");
		System.out.println("millis 1901:" + businessEffectiveDate.toGregorianCalendar().getTimeInMillis());
		System.out.println("millis 1Sep1905:" + bed1905.toGregorianCalendar().getTimeInMillis());
		System.out.println("millis 31Aug1905:" + bed31Aug1905.toGregorianCalendar().getTimeInMillis());
		System.out.println("millis 1997:" + bed97.toGregorianCalendar().getTimeInMillis());


		System.out.println("--------------------------------parsing");
		String parsed = parseDate(myDate, SHORT_DATE_PATTERN);
		System.out.println("parsed:" + parsed);
		parsed = parseDate(newD, SHORT_DATE_PATTERN);
		System.out.println("parsed newDate:" + parsed);
		parsed = parseDate(newD2, SHORT_DATE_PATTERN);
		System.out.println("parsed newDate2:" + parsed);
		parsed = parseDate(newD3, SHORT_DATE_PATTERN);
		System.out.println("parsed newDate3:" + parsed);
		parsed = parseDate(newD4, SHORT_DATE_PATTERN);
		System.out.println("parsed newDate4:" + parsed);
		
	}
	
	protected static String parseDate(Calendar cal, String aDatePattern) {
		Date date = cal != null ? cal.getTime() : null;
		return parseDate(date, aDatePattern);
	}
	protected static String parseDate(Date aDate,String aDatePattern)
	{
		if (aDate != null)
		{							
			SimpleDateFormat formatter = new SimpleDateFormat(aDatePattern);
			return formatter.format(aDate);							
		}	
		
		return null;
	}
	
	public static XMLGregorianCalendar convertDateToXMLGregorianCalendar(Date date) {
		XMLGregorianCalendar cal = null;
		if (date != null) {
			GregorianCalendar gCal = new GregorianCalendar();
			gCal.setTime(date);
			//gCal.set(date.getYear()+1900, date.getMonth(), date.getDay(), date.getHours(), date.getMinutes(), date.getSeconds());
			
			cal = dataFactory.newXMLGregorianCalendar(gCal);
		}
		return cal;
	}

Hello World!

MD:Tue Jan 01 00:00:00 CST 1901

MDSep1905:Fri Sep 01 00:00:00 CST 1905

MDAug31:Thu Aug 31 00:00:00 CST 1905

MD97:Wed Jan 01 00:00:00 CST 1997

^^^^ INIT ^^^^^--------------------------

vvvv Business Effective Date vvvvvvvv--------------------------

BED:1901-01-01T00:00:00.000-06:58

BED1Sep1905:1905-09-01T00:00:00.000-07:00

BED31Aug1905:1905-08-31T00:00:00.000-06:58

BED97:1997-01-01T00:00:00.000-06:00

myStr:1901-01-01T00:00:00.000-06:58

--------------------------------

myCal: java.util.GregorianCalendar[time=1458853089219,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/Regina",offset=-21600000,dstSavings=0,useDaylight=false,transitions=54,lastRule=null],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2016,MONTH=2,WEEK_OF_YEAR=13,WEEK_OF_MONTH=4,DAY_OF_MONTH=24,DAY_OF_YEAR=84,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=4,AM_PM=1,HOUR=2,HOUR_OF_DAY=14,MINUTE=58,SECOND=9,MILLISECOND=219,ZONE_OFFSET=-21600000,DST_OFFSET=0]

newDate from myDate:Mon Dec 31 23:59:24 CST 1900

newDate2 from 1Sep1905:Fri Sep 01 00:00:00 CST 1905

newDate3 from 31Aug1905:Wed Aug 30 23:59:24 CST 1905

newDate4 from 1997:Wed Jan 01 00:00:00 CST 1997

--------------------------------millis

millis 1901:-2177427720000

millis 1Sep1905:-2030202000000

millis 31Aug1905:-2030288520000

millis 1997:852098400000

--------------------------------parsing

parsed:1901-01-01

parsed newDate:1900-12-31

parsed newDate2:1905-09-01

parsed newDate3:1905-08-30

parsed newDate4:1997-01-01