How-To: customize Time Machine's scheduling and backup behavior

Thursday, June 19

Time Machine is purposely very limited in configurability for the sake of providing users with an easy to use yet powerful and complete backup system. The provided controls for Time Machine are essentially "on" and "off", but there are a few ways to enable other settings, which involve editing the .plist files for Time Machine. This can be done with third-party utilities, or can be done manually. Regardless of the method used, it is recommended that users back up the time machine .plist files before editing them.

The .plist files for Time Machine located in /System/Library/LaunchDaemons/ and are called:

• com.apple.backupd.plist
• com.apple.backupd-auto.plist
• com.apple.backupd-wake.plist
• com.apple.backupd-attach.plist

Utility-based approaches First, there are two utilities for modifying the schedule Time Machine keeps:

• Time Machine Scheduler
• Time Machine Editor

These programs are easy-to-use and can do what they need to quickly. If you prefer a more involved approach, however, move on:

Manual editing of the files

Change the backup interval Use any text editor to open the "com.apple.backupd-auto.plist" file, and change the "StartInterval" key value from 3600 (1 hour, in seconds) to another desired value. The value is in seconds, so calculate the value accordingly, enter it and save the 

Change the interval to a custom time, or on a specific day or date In the "com.apple.backupd-auto.plist" file you must replace the

startinterval

code along with the following

 entry to the following code for the desired backup interval:



Once a day:




	
Change the hour to the hour on the day (0 to 23)

	
Change the minute to the minute of that hour for the backup to run (0 - 59)



	StartCalendarInterval
	
		Hour
		8
		Minute
		0
	

 

Once a week:
 
Change the "Weekday" value to the day of the week you'd like the backup to run (1 for Monday)
 
Change the hour to the hour on the day (0 to 23)
 
Change the minute to the minute of that hour for the backup to run (0 - 59)
 
	StartCalendarInterval
	
		Hour
		8
		Minute
		0
		Weekday
		1
	
 

Once a month:
 
Change the "Day" to the day of the month you'd like the backup to run (1- 31).
 
Change the hour to the hour on the day (0 to 23)
 
Change the minute to the minute of that hour for the backup to run (0 - 59)
 
	StartCalendarInterval
	
		Day
		1
		Hour
		8
		Minute
		0
	
	
 
Disable the start of backups when disks are mounted Open the "com.apple.backupd-attach.plist" file and change the code to include the "disabled" key, as follows:
 
	

		Disabled
		

		Label
		...

 

To reverse the setting, remove the added code.
 
Disable the start of backups when the computer wakes from sleep or restarts Follow the instructions for #3 above and apply them to "com.apple.backupd-wake.plist"
 

Feedback? Late-breakers@macfixit.com.
 
Resources
Time Machine Scheduler
Time Machine Editor
Late-breakers@macfixit.com
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