When are "cron.monthly" cron jobs run?

Question

I want to run yum updates on a monthly basis which is actually running daily now.

Can I move 0yum-cron from cron.daily to cron.monthly? If yes, then how can we know which time and day of the month its going to run?

Answer 1

Within reason you can move anything you like between the cron.hourly, cron.daily, cron.weekly, cron.monthly.

But be careful because if you remove/move a config file installed by a package-manager such as yum then a future system upgrade might try to add the config file back. So when you move it, you might want to leave a blank file in it's place... I can't guarantee this will prevent yum from overwriting it in future.

Typically timings are configured from an entry in /etc/crontab. If you can't find anything there then check the files in /etc/cron.d

For example, on ubuntu server there is a default crontab configured specifying:

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly
25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )

According to this, my server will run it's /etc/cron.monthly scripts as root at 6:52 on the 1st of every month.