CalculateWeekDay

import java.util.*;
import java.text.*;
public class CalculateWeekDay {
public static void main(String[] args) {
Date date=new Date();
SimpleDateFormat f=new SimpleDateFormat("yyyy-MM-dd");
System.out.println(f.format(date));
String str=f.format(date);
String str1[]=str.split("-");
int year=Integer.parseInt(str1 [0]);
int month =Integer.parseInt(str1 [1]);
int day =Integer.parseInt(str1 [2]);
int total,week,i;
boolean leap=false;
leap=(year%400==0)|(year%100!=0)&(year%4==0);
week=1;
total=year-1980+(year-1980+3)/4;
for(i=1;i<=month-1;i++){
switch(i){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
total=total+31;
break;
case 4:
case 6:
case 9:
case 11:
total=total+30;
break;
case 2:
if(leap)
total=total+29;
else
total=total+28;
break;
}
}
total=total+day;
week=(week+total)%7;
System.out.print("today"+year+"-"+month+"-"+day+"is");
switch(week){
case 0:
System.out.println("Sunday");
break;
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
case 3:
System.out.println("Wednesday");
break;
case 4:
System.out.println("Thursday");
break;
case 5:
System.out.println("Friday");
break;
case 6:
System.out.println("Saturday");
break;
}
}

}