Java

package micalendario;

import java.awt.*;
import java.awt.event.*;
import java.util.Calendar;
import java.util.Locale;
import javax.swing.*;
import javax.swing.border.LineBorder;

publicclass MiCalendarioGestor extends JPanel implements MouseListener{

MiLabelCalendario select = null;
JTextField jtf= new JTextField();
Calendar cal;
JPanel pan = new JPanel();static String[] meses={"Enero", "Febrero", "Marzo", "Abril", "Mayo", "Junio", "Julio", "Agosto", "Septiembre", "Octubre", "Noviembre", "Diciembre"};
static String[] dias={"Lun", "Mar", "Mie","Jue", "Vie", "Sab", "Dom"};

JButton bAlante;
JButton bAtras;

public MiCalendarioGestor() {

this(Calendar.getInstance());
}

public void setDate(){jtf.setText( cal.get(Calendar.DATE) + " de " + meses[cal.get(Calendar.MONTH)] + " de " + cal.get(Calendar.YEAR) + "" );
}

public MiCalendarioGestor( Calendar dt ) {

setLayout(new BorderLayout());

bAlante = new JButton(">");
bAtras = new JButton("")){

auxCal.set(Calendar.MONTH, cal.get(Calendar.MONTH)+1);if ( cal.get(Calendar.DATE) > auxCal.getActualMaximum( Calendar.DAY_OF_MONTH)){
cal.set(Calendar.DATE, 1);
cal.set(Calendar.MONTH,cal.get(Calendar.MONTH)+1);
}else

cal.set( Calendar.MONTH, cal.get( Calendar.MONTH ) +1 );

}else{

auxCal.set(Calendar.MONTH,cal.get(Calendar.MONTH)-1);

if ( cal.get(Calendar.DATE) > auxCal.getActualMaximum( Calendar.DAY_OF_MONTH) ){

cal.set( Calendar.DATE, 1 );cal.set( Calendar.MONTH, cal.get( Calendar.MONTH) -1 );
}else

cal.set( Calendar.MONTH, cal.get( Calendar.MONTH) -1 );

}...