private String horario = "";
    private void definirHorario(){

        //abrir janela de informação do horário
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Definir Horario");

        // Set up the input
        final EditText input = new EditText(this);
        // Specify the type of input expected; this, for example, sets the input as a password, and will mask the text
        input.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
        builder.setView(input);

        // Set up the buttons
        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                horario = input.getText().toString();
            }
        });
        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        builder.show();
    }