gentoo-overlay/sys-fs/zfs-auto-snapshot/files/README.gentoo

Use com.sun:auto-snapshot attribute to enable snapshots for datasets
the syntax is:

zfs set com.sun:auto-snapshot=[true|false]

or:

zfs set com.sun:auto-snapshot:<frequent|hourly|daily|weekly|monthly>=[true|false]

for example:

# zfs set com.sun:auto-snapshot=false zroot
Will disalbe all snapshots for zroot and all nested datasets will inherit the property.

# zfs set com.sun:auto-snapshot=true zroot/ROOT/default
Will enable all types of snapshots for given dataset.

# zfs set com.sun:auto-snapshot:weekly=true pool/var
Will enable only weekly snapshots for given dataset.

for details please visit:
https://docs.oracle.com/cd/E19120-01/open.solaris/817-2271/ghzuk/index.html