Backups are taken of each book on a daily basis, and the last 7 days of snapshots are available for each book.
You can also take a backup manually at any time, for instance, if you're about to make a big change to your book (only your most recent manual backup is stored).
Restoring a snapshot
When you restore a backup, it creates a new book in your list with the old data. Your current book is not affected by a restore, so there's no risk in restoring.
Available on Business plans
This feature is available on our Business tier, so you may need to upgrade to get it. When you upgrade, you will already have one backup available for each book.