Cron Expression (Quartz) for a program to run every midnight at 12 am

问题

What is the cron expression in Quartz Scheduler to run a program at 12 am every midnight GMT.

I have never used quartz before so I am still learning.

Is the expression 0 0 12 * * ? or is that for 12 pm (noon). Could anyone tell me?

回答1:

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

So in your case:

0 0 0 * * ?

This will fire at midnight, if you want to fire at noon:

0 0 12 * * ?

Or both:

0 0 0,12 * * ?

A good page if you want to get more complicated: http://www.quartz-scheduler.org/documentation/quartz-2.x/tutorials/tutorial-lesson-06

Have an awesome day!

回答2:

<Minute> <Hour> <Day_of_the_Month> <Month_of_the_Year> <Day_of_the_Week>

The following graph shows what it consists of:

* * * * * *
| | | | | | 
| | | | | +-- Year              (range: 1900-3000)
| | | | +---- Day of the Week   (range: 1-7, 1 standing for Monday)
| | | +------ Month of the Year (range: 1-12)
| | +-------- Day of the Month  (range: 1-31)
| +---------- Hour              (range: 0-23)
+------------ Minute            (range: 0-59)

Cron Expression for a program to run every midnight at 12 am.

0 0 0 1/1 * ? *

A great website to create your own Cron Expression easily without much knowledge of Cron Expression : Cron Maker

It will help you build your own cron expression and show you the next firing date times of your cron like this.

1.  Wednesday, July 6, 2016 12:00 AM
2.  Thursday, July 7, 2016 12:00 AM
3.  Friday, July 8, 2016 12:00 AM
4.  Saturday, July 9, 2016 12:00 AM
5.  Sunday, July 10, 2016 12:00 AM .....

回答3:

Cron Expression for a program to run every midnight at 12 am should be 0 0 0 * * *

来源：https://stackoverflow.com/questions/11131999/cron-expression-quartz-for-a-program-to-run-every-midnight-at-12-am