GNU/Linux global system cron jobs

As well as cron jobs for each user there may also be global "system" cron jobs that run hourly, daily, weekly or monthly on your GNU/Linux system

# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/
# run-parts
01 * * * * root run-parts /etc/cron.hourly
02 4 * * * root run-parts /etc/cron.daily
22 4 * * 0 root run-parts /etc/cron.weekly
42 4 1 * * root run-parts /etc/cron.monthly

So to get a complete list of scheduled tasks (including prelink and makewhatis) try

# ls -lR /etc/cron*
-rw-r--r--  1 root root    0 Oct 27 19:08 /etc/cron.deny
-rw-r--r--  1 root root  255 Feb 21  2005 /etc/crontab
/etc/cron.d:
total 4
-rw-------  1 root root 366 Jun 14 21:19 sa-update
/etc/cron.daily:
total 84
lrwxrwxrwx  1 root root   28 Oct 27 19:07 00-logwatch -> ../log.d/scripts/logwatch.pl
-rwxr-xr-x  1 root root  418 Sep 14  2006 00-makewhatis.cron
-rwxr-xr-x  1 root root  135 Feb 21  2005 00webalizer
-rwxr-xr-x  1 root root  276 Feb 21  2005 0anacron
-rw-r--r--  1 root root  797 Feb 21  2005 certwatch
-rwxr-xr-x  1 root root  180 Oct 20  2006 logrotate
-rwxr-xr-x  1 root root 2133 Dec  1  2004 prelink
-rwxr-xr-x  1 root root  104 May  4 12:55 rpm
-rwxr-xr-x  1 root root  121 Aug 22  2005 slocate.cron
-rwxr-xr-x  1 root root  286 Feb 21  2005 tmpwatch
-rwxr-xr-x  1 root root  158 May  5 14:08 yum.cron
/etc/cron.hourly:
total 0
/etc/cron.monthly:
total 8
-rwxr-xr-x  1 root root 278 Feb 21  2005 0anacron
/etc/cron.weekly:
total 24
-rwxr-xr-x  1 root root 414 Sep 14  2006 00-makewhatis.cron
-rwxr-xr-x  1 root root 277 Feb 21  2005 0anacron
-rwxr-xr-x  1 root root  90 May  5 14:08 yum.cron