Do rados objects have a version or epoch?

Hi Ceph Dev Team, i am new to ceph and I am wondering if it would be possible to implement a command that lists all objects in a pool/namespace/rbd image that have been modified after a certain period in time? The background of this question is that I would like to implement incremental backup and restore of rbd images for a long period (e.g. 90 days daily) without keeping snapshots for each of the backups. I would instead like to store some extra info alongside with the backups that gives me the possible to later issue a call like: ceph tell me with objects of the rbd image have been changed since I made this backup and then I would like to have the opportunity to only restore those segments of the rbd that have been changed since then. I have learnt that each object has an mtime, but I have learnt that mtime is not a good choice and it would be better to have something that is strictly monotonically increasing. If there is nothing like epoch or version that can be used, would you consider mtime stable enough for this purpose if some extra time is added (e.g. does the rados object mtime have an update_interval like the rbd image mtime)? Thanks for your advice/hints, Peter