Yearly retention

[Elkropac]

Hi,
we are using btrbk to send snapshots of backuppc to remote location for 1-2 years.
We have this policy

snapshot_preserve_min      1d
snapshot_preserve          5d

target_preserve_min        1d
target_preserve            5d 5w 5m 1y

Recently, i have noticed, that yearly snapshot is from 1.1.2017 .
Is there a way to configure it in a way, that it preserves oldest snapshot, until there is new, which is one year old? Then to drop the old one and keep next until there is another one to replace it again?

Thanks,
Libor

[digint]

Sorry, I don't understand the question. What do you mean by "oldest snapshot"? Maybe an example would help.