public void calcula () {      //---------Reloj----------//
   Calendar calendario = new GregorianCalendar();
    Date fechaHoraActual = new Date();
    calendario.setTime(fechaHoraActual);
        ampm = calendario.get(Calendar.AM_PM)==Calendar.AM?"AM":"PM";

if(ampm.equals("PM")){
 int h = calendario.get(Calendar.HOUR_OF_DAY)-12;
 
 hora = h>9?""+h:"0"+h;
 if (hora.equals("00")){ hora="12";}//agrgue aqui
 else{hora=h>9?""+h:"0"+h;}//agregue aqui
}else{
 hora = calendario.get(Calendar.HOUR_OF_DAY)>9?""+calendario.get(Calendar.HOUR_OF_DAY):"0"+calendario.get(Calendar.HOUR_OF_DAY);            
}
minutos = calendario.get(Calendar.MINUTE)>9?""+calendario.get(Calendar.MINUTE):"0"+calendario.get(Calendar.MINUTE);
segundos = calendario.get(Calendar.SECOND)>9?""+calendario.get(Calendar.SECOND):"0"+calendario.get(Calendar.SECOND); 

 año= jYearChooser1.getYear();//actualizar calendario
 mes= jMonthChooser1.getMonth(); 
 jDayChooser1.setMonth(mes); 
 this.jDayChooser1.setYear(año);
         
}