Hi Bradley,
as EddieC correctly states, the version of OS X that are currently using does the periodic Daily, Weekly, Monthly scripts on a restart - if they haven't been done.
But this is now handled by launchd and not cron, as far as I know there are still a few bugs and so there is nothing stopping you from running them yourself, if you feel it is necessary.
You can edit the plist file directly, so as to allow them to run when you 'know' that your mac will be on,
Camelot, "how to change times daily/weekly/monthly runs" #1, 01:35am Sep 16, 2005 CDT
Or you could just type:
sudo periodic daily weekly monthly
(then press the return key, then your password)
into Terminal and they will all get done.
regards
Ric