How long can items in AWS Backup be retained for?

"AWS Backup can retain snapshots between 1 day and 100 years (or indefinitely, if you do not enter a retention period), and continuous backups between 1 and 35 days." This is what shows up under the "Retention period" info/description page in the Backup console when creating an AWS Backup plan.

Additionally, the AWS Backup docs say this: "Snapshot backups can be taken as frequently as every hour. Snapshot backups can be stored for up to a maximum of 100 years. Snapshots can by copied for full or incremental backups."

• Source: https://docs.aws.amazon.com/aws-backup/latest/devguide/point-in-time-recovery.html

If you're planning to keep the backup for 7 years and not planning to restore it often, then it's also a good idea to make use of lifecycle policies in the AWS Backup plan to move those backups to cold storage so you save on backup costs :) Best practice says to move the backups to cold storage after 8 days:

"If you want your backups to be incremental, you must have at least one warm backup. Because each backup to cold storage is a full backup, AWS Backup recommends that you set your lifecycle settings to not move your backup to cold storage until after at least 8 days."

• Source: https://docs.aws.amazon.com/aws-backup/latest/devguide/creating-a-backup-plan.html