Question

Write a java program MyCalendar that outputs a monthly calendar for a given month and year.
the output should be looks like this one at the bottom:( I don't know why it doesn't show right but the first day of the month is not Sunday it starts from Wednesday)

F. Last’s My Calendar
Enter month year? 10 2019
10/2019
Sun Mon Tue Wed Thu Fri Sat
---------------------------------
1 2 3 4
5 6 7 8 9 10  11
12 13 14 15 16 17 18
19 20 21   22 23 24 25
26 27 28 29 30 31

Answer 1

I think your sample output in question have problem that first day of month should be Tuesday not Wednesday. Below is correct code if you want any modification or have any problems let me know.

MyCalendar.java file:

package calendar;

import java.util.Calendar;
import java.util.Scanner;

public class MyCalendar {
  
   // main method to run program
   public static void main(String args[]) {
       // create a Scanner object to read input from user
       Scanner s = new Scanner(System.in);
       // prompt user for input date and year
       System.out.print("Enter month year? ");
       String input = s.nextLine(); // read input from user
       s.close(); // close the scanner as done reading input
       String[] data = input.split(" "); // Separate month from year
       int month = Integer.parseInt(data[0]);
       int year = Integer.parseInt(data[1]);
       // create a calendar object
       Calendar c = Calendar.getInstance();
       // set given date to calendar
       c.set(year,month-1,1); // remove 1 from month as months are 0 indexed
       // get the 1st day of the month
       int day = c.get(Calendar.DAY_OF_WEEK);
       // get maximum days of month
       int max_days = c.getActualMaximum(Calendar.DAY_OF_MONTH);
      
       // print calendar
       System.out.println(month + "/" + year); // print month
       // Format string for output days name
       String days_name = String.format("%s %s %s %s %s %s %s", " Sun","Mon","Tue","Wed","Thu","Fri","Sat");
       // print name of days
       System.out.println(days_name);
       System.out.println("----------------------------");
       //print days
       for(int i=1;i<max_days+day+1;i++) {
           int date = i - day;
           // get formated output for days
           String days = "";
           if(date > 0) {
               days = String.format("%4s", date);
           }
           else {
               days = String.format("%4s", " ");
           }
           System.out.print(days);
           //print new line at end of week
           if(i%7==0) {
               System.out.println();
           }
       }  
   }

}