final TimerConfig tc = new TimerConfig("my-timer", true);
final ScheduleExpression se = new ScheduleExpression();
final Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.SECOND, 2);
se.second(calendar.get(Calendar.SECOND) + "/3");
se.minute("*");
se.hour("*");
se.dayOfMonth("*");
se.dayOfWeek("*");
se.month("*");
timer = timerService.createCalendarTimer(se, tc);