How to Change Time Machine’s Backup Frequency

(Mac OS X 10.6.x+)
By default, Time Machine can run an automatic backup every hour. This value can be changed by following this tutorial.

Option 1: Manually Edit the Time Machine Preference File

Note: this is a more technical procedure, for those who will need to change the frequency on a regular basis, or those who would like a more user-friendly method of editing this value, please see Option 2.

1. The one-hour default is actually a «magic number» stored in a preference file; the default value of 3600 represents the number of seconds between backups.

2. The file we need to edit is located under /System/Library/LaunchDaemons

3. Open com.apple.backupd-auto.plist with a text editor on your machine (e.g., TextEdit) and find the following in the file:

   <key>StartInterval</key>
   <integer>3600</integer>
   <key>RunAtLoad</key>
   

4. As mentioned, the default value is 3600, representing 3600 seconds = 1 hour. Here are some other second values that could be used:

   Desired Frequency	Seconds
   Once an hour	3600
   Once every 2 hours	7200
   Once every 6 hours	21600
   Twice a day (12 Hours)	43200
   Once per day	86400

   • Recommended interval:
     • For laptop users, the default (once per hour) will work fine.
     • For desktop users, twice per day.

5. Replace the 3600 with the desired frequency value and save the file. As this file is a protected system file, you will be required to enter your password to save the file.

• Note: If you receive a message that you cannot save the file, try using a different text editor, as some will prompt for a system password and other will return an error message when writing over protected files. You can also change the permissions using chmod before editing, to enable writing to the file:

  >cd /System/Library/LaunchDaemons
>chmod u+w com.apple.backupd-auto.plist
  … edit the file … save the file …
  >chmod u-w com.apple.backupd-auto.plist

  If you receive a permissions error, you can use sudo chmod instead of chmod in the above script to invoke super user permissions.

1. Your Time Machine will now perform the automatic backup at the interval specified. This second-timer will start counting down from the time at which the system is turned on.

Option 2: TimeMachineEditor

TimeMachineEditor is a GUI-based software that allows the customization of how frequently Time Machine will backup. If you do not feel comfortable manually changing the frequency (or have a need to change the value quite often), this may be a more appealing option

• Go to the homepage for TimeMachineEditor
• Download the latest version of TimeMachineEditor
• Follow the installation instructions

Override Time Machine

• Go to System Preferences and open the Time Machine settings
• Turn OFF automatic backups
• Reboot your machine to ensure these changes are applied
• After rebooting, you can open TimeMachineEditor and schedule your backup on a basis of either frequency per day / week / month, OR at regularly scheduled calendar intervals (e.g., every Sunday at 2:00 AM).
• Slide the switch at the bottom left of TimeMachineEditor to the «ON» position to enable TimeMachineEditor managed backups.
  • Note: Under the Time Machine settings in System Preferences, leave the switch for automatic backups in the «OFF» postion