[Hampshire] Cron jobs for largely dormant systems (Debian)

I have set up a couple of Debian systems which will be used occasionally -
i.e. say on average twice a week, each time for about half an hour. At other
times the PC will be switched off. Looking at the crontab file this means
that all the cron jobs will never be invoked as the default run time is
around 6 in the morning. Looking through the cron scripts much of this work
is about log rotation, or checking for orphan files (lost+found), etc. I
think I should maybe run these jobs by hand occaisionally. However I am new
to Linux and haven't had experience of log rotation, etc.

Can I just invoke the scripts ad-hoc or will this not work as intended? I
notice that for example the log rotation is meant to be run daily although
the default configuration for log rotation (/etc/logrotate.conf) says
"weekly" so I suspect this will only trigger when the daily job is run on a
certain day of the week. Or maybe it will look at when it was last run and
find that this was more than a week ago?

What do others do for their home PC's if they are not on all the time?

In one system the files in cron.weekly are: man-db sysklogd
and in cron.daily are: aide apt aptitude bsdmainutils exim4-base find
logrotate man-db standard sysklogd

The other system has the same list plus a logcheck hourly cron job (which
runs on boot which is sufficient).

Russell