explain this method

i hope any one can explain this method ` private void showMonth(int m, int y) {
        int lead_spaces = 0; 
          if (m < 0 || m > 11) {
        System.out.println("It should be 1 to 12"); 
            } 
         else { 
             System.out.println(); 
             System.out.println("    " + months[m] + " " + y); 
             System.out.println();
             GregorianCalendar cal = new GregorianCalendar(y, m, 0);
             System.out.println("Su Mo Tu We Th Fr Sa "); 
             lead spaces = cal.get(Calendar.DAY OF_WEEK); 
             int day of month = days[m]; 
             if (cal.isLeapYear(cal.get(Calendar.YEAR)) && m == 1){ day of month++;} 
             for (int i = 0; i < lead_spaces; i++) { 
                 System.out.print("   "); 
                  }  

    for (int i = 1; i <= day_of_month; i++) {  
            if (i < 10) System.out.print(" ");  
              System.out.print(i);  
            if ((lead_spaces  + i) % 7 == 0) {  
               System.out.println();  
                 }   
               else {
               System.out.print(" ");  
            }  } 
         System.out.println();   }  }  



  private static void doSimpleDateFormat() {  
    Calendar now = Calendar.getInstance();  
    SimpleDateFormat formatter = new SimpleDateFormat("E yyyy.MM.dd 'at' hh:mm:ss a zzz");  
    System.out.print(" \n It is now : " + formatter.format(now.getTime()));  
     System.out.println();  
          }  


    public static void main(String[] args) {  
        String mo = JOptionPane.showInputDialog("Month");  
        String ye = JOptionPane.showInputDialog("Year");  
        int mon = new Integer(mo).intValue();  
        int yea = new Integer(ye).intValue();  
          EnglishCalendar k = new EnglishCalendar();  
              k.showMonth(mon - 1 , yea);  
         doSimpleDateFormat();

} 

plz help me