Suggest you use the Grandfather / Father / Son backup rotation scheme.
In short, it will give you something like this:
- Daily backups, kept for the time you specify (a week or a month)
- Weekly backups, kept for let’s say eight weeks
- Monthly backups, kept for say 24 months
- The current version is obviously never deleted
That way if you notice a problem within a week you can roll back to any daily version. If you don’t notice for six weeks you can roll back to a weekly version. And so on.
I use a command something like this for my purge
restic.exe --repo s3:bucketname forget --keep-daily 7 --keep-weekly 8 --keep-monthly 24