TIPS & TRICKS: Manually Change Time Machine Backup Schedule

Apple's Time Machine was, by far, the best tool Apple introduced with OS X Leopard (10.5). Backups are always the last thing most users think about. But, it's the first thing people wish they would have had when there's some failure that prevents them from accessing their data. Time Machine's simplicity should have every single person who doesn't already have a backup solution adopt it with fervor.

As great as the tool is for most backup needs, I have discovered a drawback. Time Machine runs a backup once an hour. The constant barrage of data hitting the backup destination can put a toll on the media. In many cases, the media is an external hard drive with physical hard drive. The drives themselves are not nearly as sturdy as they used to be. I've come across users who have had to replace their backup drives inside of 6 months. If you need the once an hour backup interval, then you'll need to put up with this routine maintenance. Think of it as changing the oil filter every time you change your oil in the car.

Fortunately, there is a fix for those people who don't need the backups nearly that frequently. As the saying goes, there's an app for this. However, I am an fan of understanding how the underlying code works. The manual method is this command (all one line):

sudo defaults write /System/Library/LaunchDaemons/com.apple.backupd-auto StartInterval -int 14400

The 14400 is the number of seconds in 4 hours. The number you choose should be a factor of 3600 seconds (1 hour). For example if you want to do it once every 7 days, you would use 604800. You can also check the change with this command:

sudo defaults read /System/Library/LaunchDaemons/com.apple.backupd-auto StartInterval

Hope this helps you out with extending the life of that backup hard drive.