zfSnap is a simple sh script for creating ZFS snapshots. When called from
cron rolling snapshots can be created and deleted automatically. The main
advantage of zfSnap is that it is written in 100% pure /bin/sh, does not
require any additional software to run, and is simple to use.

zfSnap keeps all information about snapshot in snapshot name. zfs snapshot
names are in form: Timestamp--TTL where timestamp is date and time of
snapshot creation and TTL is Time To Live in human readable form.

WWW: https://github.com/zfsnap/zfsnap