cron every hour question.

EDIT>>> found this. Does everyone get these 17th minute of the hour cron entries.

"That's easy, the 17th minute one is just cron.hourly firing off. Even if it's empty (I just realized this), cron will still log in /var/log/auth.log even if there was nothing to do, because it still did fire off."

http://ubuntuforums.org/showthread.php?t=905193

I was looking in auth.log and noticed that cron has been doing something every hour but when I look at etc/cron/hourly there is nothing but a placeholder.

I installed cron-apt to do daily updates which runs as expected once per day.

Any ideas what is happening?

edit. in /etc/cron.d there is just 2 files .placeholder and cron-apt (which says to run once per day)

nothing in /var/spool/cron/crontabs

in /etc/cron.daily , there is listed

standard

passwd

ntp

mlocate

man-db

logrotate

exim4-base

dpkg

bsdmainutils

aptitude

apt.

I did install exim but nothing else .