The Cloud Server Backup Service (CSBS) provides improved retention rules setting possibilities. You will be able to retain what you really want. From this release it is available to set long-term retention rules for daily, weekly, monthly, yearly basis. Long-term retention rules can be effective together with quantity-based retention settings.
New option can be found on CSBS console policy editor in retention rule settings as Long-term retention settings drop-down menu. Here you can set the retention backups what you need, and CSBS manage it for you.
Further information can be found in the CSBS area of the Help Center.