Backups & restore points · When backups run
What happens if my Mac is asleep when a scheduled backup is due?
Short answer: It backs up once when the Mac is next able to — not once for every missed slot — so a week away means one catch-up backup, not a burst of them.
It backs up once when it's next able — not once for every slot it missed. So after a week away you get one backup when you're back, not a burst of seven.
If the Mac is shut down or Storage Studio isn't running, the app also does a catch-up when it next opens, finishing anything that didn't complete.