Implementation of a human readable date display

getHumanReadableDateDisplay.java

/**
 * An implementation on getting the human readable date format from milliseconds
 * which is commonly used in Facebook, like about x hours ago.
 * Convention as follows:
 * 1000 milliseconds = 1 second,
 * 60 seconds = 1 minute,
 * 60 minutes = 1 hour,
 * 24 hours = 1 day,
 * 12 days = 1 month,
 * 12 month = 1 year.
 */
private static String getHumanReadableDateDisplay(long pastMillisecond){
	Calendar cal = Calendar.getInstance();
		
	long currentMillisecond = cal.getTimeInMillis();
	long diff = currentMillisecond - pastMillisecond;
	
	int[] units = new int[] {1000,60,60,24,30,12};
	String[] unitName = new String[] {"seconds", "minutes", "hours", "days", "months", "years"};
	double f = diff;
	
	int bound = 1;
	int i = 0;
	int j = 0;
	
	long roundedValue = 0;
	while (bound <= 1 && i < units.length){
		
		f = f/units[i];
		bound = Double.compare(f, 1);
		roundedValue = Math.round(f);
		
		
		if (roundedValue <= 1){
			roundedValue = Math.round(f * units[i]);
			return "about "+ roundedValue + " "+unitName[j-1]+ " ago";
			
		}else{
			//System.out.println(i+"("+f+"/"+units[i]+") : about "+ roundedValue + " "+unitName[j]);
			i++;
			j++;
		}
		
	}//end of while
	return "about "+ roundedValue + " "+unitName[j-1]+ "ago";
}