[Ganesha]

Tiger no longer uses cron to run these jobs, instead Apple is using launchd. This requires a slightly different approach changing the timing of these tasks.

Mac OS X 10.4 has as changed the method by which the periodic system tasks periodic daily, weekly and monthly are called. You can no longer change their execution time by modifying the system crontab. If you wish to change the times these tasks run you will have to make changes to the follow files.

Code:
/System/Library/LaunchDaemons/com.apple.periodic-daily.plist
/System/Library/LaunchDaemons/com.apple.periodic-weekly.plist
/System/Library/LaunchDaemons/com.apple.periodic-monthly.plist

Since these files are owned by root, the easiest way to change them is with sudo and your favorite command line text editor.

Code:
(ex. sudo pico System/Library/LaunchDaemons/com.apple.periodic-daily.plist)

The relevant parts to change are.

Code:
<key>Hour</key>
<integer>3</integer>
<key>Minute</key>
<integer>15</integer>

to whatever you like.

(Also submitted to maxosxhints)

[t_hah]

If I run the usual sudo periodic daily weekly monthly command in the Terminal, it still executes. Is there something I should be concerned about, or did that part of the process stay the same?

[yaro]

So where do I put my weekly cron scripts for execution?

[Ganesha]

Originally Posted by yaro

So where do I put my weekly cron scripts for excution?

You have two choices... Use cron like you always did. By default cron is off, but Apple's made it in Tiger that cron will turn if you have cron jobs the need running.

If you want to migrate them as a lunchd task put them...

Code:
~/Library/LaunchAgents         Per-user agents provided by the user.
/Library/LaunchAgents           Per-user agents provided by the administrator.

...keep in mind the format for running launchd jobs is different then cron.