Time Machine just does what it does and there’s not much controlin’ it aside from what’s in the System Preference pane. Or is there? Earlier, I covered how to disable the disk check feature, now let’s look at how to change the frequency of when backups occur. Backups are initiated by com.apple.backupd-auto.plist, stored in /System/Library/LaunchDaemons. The contents of this file are, by default:
<?xml version=”1.0″ encoding=”UTF-8″?>
<!DOCTYPE plist PUBLIC “-//Apple Computer//DTD PLIST 1.0//EN” “http://www.apple.com/DTDs/PropertyList-1.0.dtd”>
<plist version=”1.0″>
<dict>
<key>Label</key>
<string>com.apple.backupd-auto</string>
<key>ProgramArguments</key>
<array> <string>/System/Library/CoreServices/backupd.bundle/Contents/Resources/backupd-helper</string>
<string>-auto</string>
</array>
<key>StartInterval</key>
<integer>3600</integer>
<key>RunAtLoad</key>
<false/>
<key>KeepAlive</key>
<false/>
</dict>
</plist>
The StartInterval integer controls the frequency with which backups occur, in seconds. You can customize this by altering the data in the line below (the integer). For example, if you set it to 360 then backups will occur every 6 minutes instead of 60, or more likely, if you set the integer to 14400 then your backups will occur every 4 hours instead of every hour.