How to put an Invalid Month output?

[sonk]

Date Input from month 13,14,15 and above are continuously making an Zodiac Sign output, it should be an invalid month. How can i fix it?======================================================================================\[code\]import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar;import java.util.Scanner;public class MainTab{ public String[] chineseZodiac = new String[] { "Monkey","Rooster","Dog","Pig","Rat","Ox","Tiger","Rabbit","Dragon", "Snake","Horse","Sheep" }; public String[] zodiacSigns = new String[] { "Capricorn","Aquarius","Pisces","Aries","Taurus","Gemini", "Cancer","Leo","Virgo","Libra","Scorpio","Sagittarius" }; public static void main(String[] args) { Scanner s = new Scanner(System.in); MainTab x = new MainTab(); SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy"); System.out.printf("Enter a date (MM/dd/yyyy): "); String input = s.nextLine(); Calendar cal = Calendar.getInstance(); try { Date date = sdf.parse(input); cal = new GregorianCalendar(); cal.setTime(date); } catch (ParseException pe) { pe.printStackTrace(); } System.out.printf(" Your Chinese Zodiac Sign is: %s\n", x.getChineseZodiac(cal.get(Calendar.YEAR))); System.out.printf(" Your Zodiac Sign is: %s\n", x.getZodiac(cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH))); } public String getZodiac(int month, int day) { if((month == 11) && ( day>= 22) || (month == 0) && (day <= 19)) { return zodiacSigns[0]; }else if((month == 0) && (day >= 20) || (month == 1) && (day <= 18)) { return zodiacSigns[1]; } else if((month == 1) && (day >= 19) || (month == 2) && (day <= 20)) { return zodiacSigns[2]; } else if((month == 2) && (day >= 21) || (month == 3) && (day <= 19)) { return zodiacSigns[3]; } else if((month == 3) && (day >= 20) || (month == 4) && (day <= 20)) { return zodiacSigns[4]; } else if((month == 4) && (day >= 21) || (month == 5) && (day <= 20)) { return zodiacSigns[5]; } else if((month == 5) && (day >= 21) || (month == 6) && (day <= 22)) { return zodiacSigns[6]; } else if((month == 6) && (day >= 23) || (month == 7) && (day <= 22)) { return zodiacSigns[7]; } else if((month == 7) && (day >= 23) || (month == 8) && (day <= 22)) { return zodiacSigns[8]; } else if((month == 8) && (day >= 23) || (month == 9) && (day <= 22)) { return zodiacSigns[9]; } else if((month == 9) && (day >= 23) || (month == 10) && (day <= 21)) { return zodiacSigns[10]; } else if((month == 10) && (day >= 23) || (month == 11) && (day <= 21)) { return zodiacSigns[11]; // } else if((month == 13) || (month == 14) || (month == 15)) {// return zodiacSigns[12]; } return null; } public String getChineseZodiac(int year) { return chineseZodiac[year%12]; } }\[/code\]=====================================================================================