what is the meaning of the below cron expressions

chaitu chaitu
chaitu chaitu used Ask the Experts™
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what is the meaning of the below cron expressions?

is it going to every 1 min 30 secs or 1 hr 30 mins?

30 0/1 * * * ?

is it going to every 2 mins or 2 hr?

0 0/2 * * * ?
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Top Expert 2016

Commented:
Not a Java question!

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Commented:
where do i place this question?In java also we can use these quartz cron expressions right..
Great, this isn't a java question, so I might actually be able to answer it :-).

First example you give: 30 0/1 * * * ?
Fire at 30 seconds every 1 minute. So 13:00:30, 13:01:30, 13:02:30 etcetera

Second example: 0 0/2 * * * ?
Fire every 2 minutes at 00 seconds. So 13:00:00, 13:02:00, 13:04:00 etcetera

Both will be executed every day.
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Top Expert 2016

Commented:
30 0/1 * * * 

Open in new window

At every 30th minute past every hour
0 0/2 * * *

Open in new window

On the hour every two hours

Both the above every day

Seconds do not have a field of their own
Aha! Thanks, seconds don't have a field. That sure solves a  cron mystery for me!

Not sure how I missed that, as the example is quite obvious....
 # ┌───────────── min (0 - 59)
 # │ ┌────────────── hour (0 - 23)
 # │ │ ┌─────────────── day of month (1 - 31)
 # │ │ │ ┌──────────────── month (1 - 12)
 # │ │ │ │ ┌───────────────── day of week (0 - 6) (0 to 6 are Sunday to Saturday, or use names; 7 is Sunday, the same as 0)
 # │ │ │ │ │
 # │ │ │ │ │
 # * * * * *  command to execute
Top Expert 2016

Commented:
???

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