Editing Apple’s Time Machine via .plist or Terminal
If, like me, you have a Mac running OSx 10.5.x a.k.a. Leopard, then you will be using Time Machine. Time Machine for those who don’t know, is the automated backup utility that is so easy to use – really all you need to do is plug in an external hard drive (usb or firewire) then turn the service on
System Preferences
System Preferences >
Time Machine
Time Machine >
Time Machine Settings
As soon as you have an external hard drive added Time Machine will ask you if you want to use this drive to back up your data. That is pretty much all you have to do.
So why are there no more settings? Well according to Apple they wanted to make a fool proof system that just works. That is why you cannot decided which time of day you want to back up.
Well this is true until I tell you about plists. 
There is a plist called
com.apple.backupd-auto.plist: (look in /System/Library/LaunchDaemons/)
The line that we need to edit is
<key>StartInterval</key>
to something like:
<key>StartInterval -int 1800</key>
OK, so two ways to do this. 1. Directly via the plist, but I’m guessing you don’t have access to change this file.
If you check the file’s info (when in Finder, CTRL + Left Click, choose ‘Get Info’)
Permissions
So to edit the permission, click the little padlock and enter your Administrator password. If you don’t know the admin password stop reading now as you can’t complete this task without it.
Add your own profile name and change permissions to read / write. (you can change back to read only once we are done, or better still, delete your profile from the list, back to when we started, but keep ‘system, wheel & everyone’ otherwise you will block this from working at all.
If this doesn’t work, drag the file to your desktop, make the changes, save, copy back into the original folder and enter you admin password to Authenticate.
Personally I would not even do it this way, after all, that’s what the Terminal is for.
Terminal
Open Finder, go to APPLICATIONS > Utilities > Terminal.app (or search Terminal from spotlight)
type the following:
sudo defaults write /System/Library/LaunchDaemons/com.apple.backupd-auto StartInterval -int 1800
Terminal plus code
add your admin password, hit enter.
All done.
Hope that helps.
Now, I hope other admins jump in with better ways to do this or point out that I only wrote info for single user mode. Please, fill in the gaps.
and this Freeware program does it for you if you can’t keep up ~
http://www.versiontracker.com/dyn/moreinfo/macosx/33757#screenshots
Thanks Jonah, please let me know if you like the Freeware.
Generally have a rule of no comments unless I can add something of value. All I know is that I’m tired of having computer problems and trying to manage my back-ups as well. Yes, I’m currently a windows user and I’m grateful for your reinforcing words on the immediate benefit of using a mac. I’m coming over on the next purchase.
@Dan, have you left the Dark Side yet?
The Apple backup is by far the best backup I have ever used. It is a hog on disk space, but I just bought a 1TB external drive for $99. That should give me about 2 months backup on my MBP.
@Angie: Backups are essential, but remember, even for home, that you should have multiple backups or use at least RAID1 – instead of a simple External Hard Drive you may want to look into a cheap NAS.
blog.smoothape.com – da best. Keep it going!
Thanks
I promise to.
Thank you so much for the over-write idea on the plist file. I couldn’t save the file NO MATTER what I did with the permissions. But dragging and dropping worked fine.
Honestly that’s the one thing that drives me batty about macs – I’m an admin – let me do whatever I want please.
@KMO – Real people think it is crazy, the computer thinks it is 100% logical.