第35分钟的每小时运行一次的cron cron

Question

I have a job that is scheduled to run every hour and I am using spring cron (0 0/35 * * * ). I am expecting the job to run at the 35th minute every hour but I noticed that the job gets triggered at the 35th minute and also at top of the hour. I am not sure why, any suggestions?

Thanks, Karthik

Answer 1

根据Spring CronSequenceGenerator的文档 ， /35 in 0 0/35 * * *实际上表示“每分钟是35的倍数”，其中包括0-如果您只希望它在每小时后的35分钟触发，请使用0 35 * * * * （包括所需的所有6个参数）。

Answer 2

您的cron表达式不正确，因此请将其更改为0 */35 * * * ，该表达式仅每35分钟运行一次

Answer 3

I think your fields are out of order. The Spring Cron documenation seems to say that Spring uses standard cron expressions. https://crontab.guru is a good tool for checking cron expressions.

https://crontab.guru/#0_0/35_ _ _* shows

“At minute 0 past every 35th hour from 0 through 23.”

Whereas https://crontab.guru/#35_ _ _ _ shows

“At minute 35.”

I think you need to use 35 * * * *

Answer 4

Yes. Cron starts minutes at beginning of each hour (as we mention * for hour field). An alternative way of achieving your goal ( executing a task at every 35th minute )can be as follows -

Make your cron trigger for every 5 minutes and increment a counter everytime the cron is triggered. Once the counter reaches 7 (ie 35 mins in your case), execute your goal and set the counter back to 0.

And if you want your goal to be executed at 35th minute of each hour , you should try

35 * * * *

Hope this helps!