Cron expression to schedule a job every two years

问题

I'm building a Quartz cron expression to schedule a job to run on a specific day every two years from today. I've tested quite a few but I think one of the following should do the work:

53 18 23 12 ? 2013/2 => starting on year 2013 and on every two years later on
53 18 23 12 ? */2

But both of them fail the Quartz cron expression validation test. What could be the right cron expression?

回答1:

Your Cron expression is incomplete. Quartz Cron expressions are made up of seven parts:

1. Seconds
2. Minutes
3. Hours
4. Day-of-Month
5. Month
6. Day-of-Week
7. Year (optional)

So if you wanted to set up a schedule to run at 11:59pm on Dec 24th every two years starting in 2013, the expression would be:

0 59 23 24 12 ? 2013/2

来源：https://stackoverflow.com/questions/20745514/cron-expression-to-schedule-a-job-every-two-years