Hi COGordo,
One of the most overlooked (and under used) apps. in OS X is Automator.
People don't use it because they find it intimidating however it is not that hard to use.
If you play with the app. you will quickly get a feel for it. It also allows you to "step" thru it to make sure you have it right.
I prefer manual updates and wait until there's a dot update for major OS releases. I have been burnt too many times on the "bleeding edge".
Since I don't allow automatic updates (but do allow automatically check for updates) I don't have a script that I can share with you.
You will want to check that an update is available and then run the /System/Library/CoreServices/Software Update.app. with time parameters you have scripted (based on your local time zone).
Hope this helps!
Don :)
P.S. The easy way is to use the scheduler under energy savings unless you want to learn to write a little script.
