Change Time Machine Options preferences on Mac
On your Mac, use Time Machine Options preferences to specify items you want to exclude from backups and change other options.
To change these preferences, choose Apple menu > System Preferences, click Time Machine, then click Options.
List of excluded items
Items you selected to exclude from backups.
To exclude items from backups, click the Add button , select the items, then click Exclude.
To remove an item from the list, select it, then click the Remove button . The item will be included in the next Time Machine backup.
Back up while on battery power (portable computers only)
Create backups every hour even if your Mac is on battery power.
Exclude system files and applications
Automatically exclude macOS system files and apps from backups.
When you select this checkbox, the system files and apps don’t appear in the list of excluded items.
Note: It’s not recommended to use this option. When you do, you can’t use Time Machine to restore your system if your startup disk is damaged. Instead you must reinstall macOS on your Mac, then use Migration Assistant to transfer your information from a Time Machine backup or other storage device.