Thread.sleep问题求解

用的quartz定时任务

代码：
log.info("afternoon task start...");
long delay = random.nextInt(3600) * 1000;
log.info("sleep " + delay + " ms");
Thread.sleep(delay);
log.info("afternoon send start...");

日志：
[INFO ] 2017-09-12 18:00:00,456 16896832 DefaultQuartzScheduler_Worker-1 core.AfternoonJob core.AfternoonJob.send(AfternoonJob.java:20) afternoon task start...
[INFO ] 2017-09-12 18:00:00,457 16896833 DefaultQuartzScheduler_Worker-1 core.AfternoonJob core.AfternoonJob.send(AfternoonJob.java:23) sleep 2655000 ms

然后就没有然后了，按理来说18:44应该要执行的

会不会是中间停服务了，不过这样写有什么意义吗?想要18:44执行直接用cron表达式指定时间不就行了吗