Date Validator Java

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class DateValidator {

 private static Pattern pattern;
 private static Matcher matcher;

 // pattern dd/mm/yyyy
 private static final String DATE_PATTERN_DD_MM_YYYY = "(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\\d\\d)";
 // pattern mm/dd/yyyy
 private static final String DATE_PATTERN_MM_DD_YYYY = "(0?[1-9]|1[012])/(0?[1-9]|[12][0-9]|3[01])/((19|20)\\d\\d)";

 public static void main(String args[]){

        System.out.println(validate("05/12/2013"));
    }
 public static boolean validate(final String value) {
  pattern = Pattern.compile(DATE_PATTERN_MM_DD_YYYY);
  matcher = pattern.matcher(value);
  return matcher.matches();
 }

}