Date8.java

 public class Date8 { 
 private int month; 
 private int day; 
 private int year;
 private static final int[] daysPerMonth = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };   
 public Date8(int day, int month, int year){ 
  if (month <= 0 || month > 12) 
  throw new IllegalArgumentException( "month (" + month + ") must be 1-12");
  if (day <= 0 ||  (day > daysPerMonth[month] && !(month == 2 && day == 29))) 
  throw new IllegalArgumentException("day (" + day +  ") out-of-range for the specified month and year"); 
  if (month == 2 && day == 29 && !(year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)))
  throw new IllegalArgumentException("day (" + day +  ") out-of-range for the specified month and year"); 
  this.month = month; 
  this.day = day; 
  this.year = year; 
  System.out.printf("Date object constructor for date %s%n", this); 
  } 
 public String toString() { 
 return String.format("%d/%d/%d", day,month, year); 
 } 
 public void nextday(){
  day +=1;
  if (day >daysPerMonth[month]){
    day= 1;
    month+=1;
	if(month>12){
		month=1;
	    year+=1;
	}
   }
	System.out.printf("after incrementation of OF day the new  date is %s%n",this);
  }
 }