Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a question. We have a cron job that executed on the 15th of this month:

min hr day month day_of_week
35  13 15  6     6

However, it executed again on June 22nd (which was the 6th day of the week). Would the day_of_week take precedence over day & month that was already set before?

share|improve this question
up vote 3 down vote accepted

While normally the job is executed when the time/date specification fields all match the current time and date, there is one exception: if both "day of month" and "day of week" are restricted (not "*"), then either the "day of month" field (3) or the "day of week" field (5) must match the current day

So it happens only in June, at 13:35. Additionally it needs to be EITHER the 15th of June, or the 6th day of the week. Both at once will work too.

Running man 5 crontab will give you some additional information, they recommend you use test to specify both a specific date and restrict the weekday :

Note: The day of a command's execution can be specified by two fields — day of month, and day of week. If both fields are restricted (i.e., aren't *), the command will be run when either field matches the current time. For example, ``30 4 1,15 * 5'' would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday. One can, however, achieve the desired result by adding a test to the command (see the last example in EXAMPLE CRON FILE below).


# Run on every second Saturday of the month
0 4 8-14 * *    test $(date +\%u) -eq 6 && echo "2nd Saturday"
share|improve this answer
So you think give the setup, repeat of the cron is possible? Since the day of the month & day of the week are both restricted, it would work on either of the dates. – brooding_goat Jun 24 '13 at 21:57
Yes. It will run again on 29.06.2013 13:35, because that will meet the requirements of minute, hour, month, and day of the week. – Squeezy Jun 24 '13 at 22:03
thanks. So how do we say that run only on 15th of the month. Do we put * for the day of the week? – brooding_goat Jun 24 '13 at 22:06
Yes. If you want to run it on the 15th of ANY month, not only June, also put * for month. – Squeezy Jun 24 '13 at 22:08

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.