Need help to explanation of the code

[aappee]

Hi, need help as to what is the code doing, if possible each statement if anyone knows:
When it is run, when dd/mm/yyyy format is enter, it will give 20 Dec 2010 is a Monday
Why is the monthIndices and division done for ?

public static String dayOfWeek(int dd, int mm, int yyyy) {
			int[] monthIndices = {1,4,4,0,2,5,0,3,6,1,4,6};
			String[] dayOfWeek = {"Saturday", "Sunday", "Monday", 
			                      "Tuesday", "Wednesday", "Thursday", 
			                      "Friday"};
			if ((yyyy % 4 == 0) && !(yyyy % 100 == 0) || 
			    (yyyy % 400 == 0)){
				monthIndices[0] = 0;
				monthIndices[1] = 3;
			}
			int yy = yyyy % 100;
			int yyDiv4 = yy / 4;
			int keyNumber = monthIndices[mm-1];
			int sum = yy+yyDiv4+keyNumber+dd;
			int adjValue = 0;
			if (yyyy / 100 == 18)
				adjValue = 2;
			else 
				if (yyyy / 100 == 20)
					adjValue = 6;
				else
					if (yyyy / 100 == 21)
					adjValue = 4;
			int remainder = (sum + adjValue) % 7;
			String day = dayOfWeek[remainder];
			return day;
			}
		}

[javaAddict]

Why don't you ask the person whose code you copied? It is obvious that it returns the day.

If you want a code that returns the day then write your own and post it here with questions in order to get help. You can use the java.text.SimpleDateFormat class, if you are allowed.

[kramerd]

It looks like the author of the code you found is doing something slightly different from this algorithm, but only slightly. This might help you understand what the code is doing.

[aappee]

ok, this is from my lecturer for the exam revision but his lesson has ended i can email to him but it would be easy to ask in a forum of discussion.

Thanks for the info, i'll read up, hope it helps my exam :)