DST and Leap Secondes Test Java

DstAndLeapSecondsTest.java

import java.util.*;

public class DstAndLeapSecondsTest{
	
	public static void main(String[] args){
		
		Calendar start, old, curr;
		long diff;
		
		start = Calendar.getInstance();
		start.set(Calendar.YEAR, 2012);
		start.set(Calendar.MONTH, Calendar.JANUARY);
		start.set(Calendar.DAY_OF_MONTH, 1);
		start.set(Calendar.HOUR_OF_DAY, 0);
		start.set(Calendar.MINUTE, 0);
		start.set(Calendar.SECOND, 0);
		start.set(Calendar.MILLISECOND, 0);
		
		old = (Calendar)start.clone();
		old.setTimeZone(TimeZone.getTimeZone("UTC"));
		System.out.println("set - " + old.getTimeZone().getDisplayName());
		for (int i = 3; i <= 72; i += 3){
			curr = (Calendar)old.clone();
			curr.set(Calendar.YEAR, 2012 + i / 12);
			curr.set(Calendar.MONTH, Calendar.JANUARY + i % 12);
			diff = curr.getTimeInMillis()-old.getTimeInMillis();
			System.out.println(old.getTime().toString() + "-->" + curr.getTime().toString() + ": " +
				diff/1000 + " s = " + diff / (24.*60*60*1000) + " days" + " (" +
				diff % (24*60*60*1000) /1000 + " s)");
			old = curr;
		}
		
		old = (Calendar)start.clone();
		old.setTimeZone(TimeZone.getTimeZone("Europe/Berlin"));
		System.out.println("set - " + old.getTimeZone().getDisplayName());
		for (int i = 3; i <= 72; i += 3){
			curr = (Calendar)old.clone();
			curr.set(Calendar.YEAR, 2012 + i / 12);
			curr.set(Calendar.MONTH, Calendar.JANUARY + i % 12);
			diff = curr.getTimeInMillis()-old.getTimeInMillis();
			System.out.println(old.getTime().toString() + "-->" + curr.getTime().toString() + ": " +
				diff/1000 + " s = " + diff / (24.*60*60*1000) + " days" + " (" +
				diff % (24*60*60*1000) /1000 + " s)");
			old = curr;
		}
		
		old = (Calendar)start.clone();
		old.setTimeZone(TimeZone.getTimeZone("UTC"));
		System.out.println("add - " + old.getTimeZone().getDisplayName());
		for (int i = 0; i < 24; i++){
			curr = (Calendar)old.clone();
			curr.add(Calendar.MONTH, 3);
			diff = curr.getTimeInMillis()-old.getTimeInMillis();
			System.out.println(old.getTime().toString() + "-->" + curr.getTime().toString() + ": " +
				diff/1000 + " s = " + diff / (24.*60*60*1000) + " days" + " (" +
				diff % (24*60*60*1000) /1000 + " s)");
			old = curr;
		}
		
		old = (Calendar)start.clone();
		old.setTimeZone(TimeZone.getTimeZone("Europe/Berlin"));
		System.out.println("add - " + old.getTimeZone().getDisplayName());
		for (int i = 0; i < 24; i++){
			curr = (Calendar)old.clone();
			curr.add(Calendar.MONTH, 3);
			diff = curr.getTimeInMillis()-old.getTimeInMillis();
			System.out.println(old.getTime().toString() + "-->" + curr.getTime().toString() + ": " +
				diff/1000 + " s = " + diff / (24.*60*60*1000) + " days" + " (" +
				diff % (24*60*60*1000) /1000 + " s)");
			old = curr;
		}
	}
}