DynamoDB on-demand backup expiry date

Question: What is the expiry date  for an AWS DynamoDB ON-DEMAND backup ?   I have a list of backups which are created using the ON-DEMAND feature and I am reviewing how we manage these ad-hoc backups

Answer: AWS DynamoDB on-demand backups using the DynamoDB API have no expiry date . It is an independent backup sperate from backups is AWS Backup. 

The on-demand backups  are classed as USER BackupTypes  , separate from SYSTEM backups which have a built-in lifecycle management process and which you can Recover deleted DynamoDB table with Point-In-Time Recovery Enabled 

To manage the lifecycle of these USER backups , you'll need to explicitly delete. 

For future requirements - consider using AWS Backup service - if it is enabled and configured for your organization - as the AWS Backup Service has built-in lifecycle management facility

When you call a DynamoDB USER  there is no Expiry date set 

aws dynamodb list-backups --table-name TEST --output table
-------------------------------------------------------------------------------------------------------------------
| ListBackups |
+-----------------------------------------------------------------------------------------------------------------+
|| BackupSummaries ||
|+------------------------+--------------------------------------------------------------------------------------+|
|| BackupArn | arn:aws:dynamodb:xxxxx:xxxxxxxxxxxxx:table/TEST/backup/111111111111111 ||
|| BackupCreationDateTime| 2023-03-20T13:27:32.716000+00:00 ||
|| BackupName | TEST ||
|| BackupSizeBytes | 0 ||
|| BackupStatus | AVAILABLE ||
|| BackupType | USER ||
|| TableArn | arn:aws:dynamodb:xxxxx:xxxxxxxxxx:table/TEST ||
|| TableId | 111111111111111 ||
|| TableName | TEST ||
|+------------------------+--------------------------------------------------------------------------------------+|

When you call the details of a DynamoDB SYSTEM database there is an expiry date associated 

aws dynamodb list-backups --backup-type SYSTEM --table-name myTable --output table
--------------------------------------------------------------------------------------------------------------------
| ListBackups |
+------------------------------------------------------------------------------------------------------------------+
|| BackupSummaries ||
|+------------------------+---------------------------------------------------------------------------------------+|
|| BackupArn | arn:aws:dynamodb:xxxxx:xxxxxxxxx:table/mytable/backup/11111111111111 ||
|| BackupCreationDateTime| 2024-02-20T09:10:21.330000+00:00 ||
|| BackupExpiryDateTime | 2024-03-26T09:10:21.330000+00:00 ||
|| BackupName | myTable$DeletedTableBackup ||
|| BackupSizeBytes | 143 ||
|| BackupStatus | AVAILABLE ||
|| BackupType | SYSTEM ||
|| TableArn | arn:aws:dynamodb:xxxxxxx:111111111111:table/xxxxxxxxx ||
|| TableId | 1111111111111111111111 ||
|| TableName | myTable ||
|+------------------------+---------------------------------------------------------------------------------------+|