Question

how to correct this java code so that i get the correct day of week?

and test the year

public static void main(String[] args) {
       //
      
      
Scanner s = new Scanner(System.in);

//needed info
//year month, day
int year, month, dayOfMonth;

// add day of week , century yr
int dayOfWeek, century, yearOfCentury;
  
//user inputs year
System.out.print("Enter year: (example, 2020):");
year = s.nextInt();

//user inputs month by number
System.out.print("Enter month: 1-12:");
month = s.nextInt();


//user inputs day of month
System.out.print("Enter the day of the month: 1-31:");
dayOfMonth = s.nextInt();

// testing if month is January or February
if(month == 1) {
month = 13;
} else if(month == 2) {
month = 14;
}

//determining year month
century = year / 100;
yearOfCentury = year % 100;
dayOfWeek = (dayOfMonth + ((26 * (month + 1))/10) + yearOfCentury + yearOfCentury/4 + century/4 + century * 5) % 7;
  

//figuring out day
if(dayOfWeek == 0) {
System.out.print("Day of the week is Saturday.");
}
else if(dayOfWeek == 1) {
System.out.print("Day of the week is Sunday.");
}
else if(dayOfWeek == 2) {
System.out.print("Day of the week is Monday.");
}
else if(dayOfWeek == 3) {
System.out.print("Day of the week is Tuesday.");
}
else if(dayOfWeek == 4) {
System.out.print("Day of the week is Wednesday.");
}
else if(dayOfWeek == 5) {
System.out.print("Day of the week is Thursday.");
}
else if(dayOfWeek == 6) {
System.out.print("Day of the week is Friday.");
}

}
}

Answer 1

Please find the answer below.
Please do comments in case of any issue. Also, don't forget to rate the question. Thank You So Much.

DayOfWeekDebug.java

package classes15;

import java.util.Scanner;

public class DayOfWeekDebug {

   public static void main(String[] args) {
       //
       Scanner s = new Scanner(System.in);
      
       //needed info
       //year month, day
       int year, month, dayOfMonth;

       // add day of week , century yr
       int dayOfWeek, century, yearOfCentury;

       //user inputs year
       System.out.print("Enter year: (example, 2020):");
       year = s.nextInt();
       if(year<0) {
           System.out.println("Error!!! Invalid year is entered.");
           return;
       }

       //user inputs month by number
       System.out.print("Enter month: 1-12:");
       month = s.nextInt();

       //user inputs day of month
       System.out.print("Enter the day of the month: 1-31:");
       dayOfMonth = s.nextInt();

       // testing if month is January or February
       if(month == 1) {
           month = 13;
       } else if(month == 2) {
           month = 14;
       }

       //determining year month
       century = year / 100;
       yearOfCentury = year % 100;
       dayOfWeek = (dayOfMonth + ((26 * (month + 1))/10) + yearOfCentury + yearOfCentury/4 + century/4 + century * 5) % 7;

       //figuring out day
       if(dayOfWeek == 0) {
           System.out.print("Day of the week is Saturday.");
       }
       else if(dayOfWeek == 1) {
           System.out.print("Day of the week is Sunday.");
       }
       else if(dayOfWeek == 2) {
           System.out.print("Day of the week is Monday.");
       }
       else if(dayOfWeek == 3) {
           System.out.print("Day of the week is Tuesday.");
       }
       else if(dayOfWeek == 4) {
           System.out.print("Day of the week is Wednesday.");
       }
       else if(dayOfWeek == 5) {
           System.out.print("Day of the week is Thursday.");
       }
       else if(dayOfWeek == 6) {
           System.out.print("Day of the week is Friday.");
       }

   }

}