15,30,45 * * * * root /usr/local/sbin/zfs-auto-snapshot frequent  4
0        * * * * root /usr/local/sbin/zfs-auto-snapshot hourly   24
7        0 * * * root /usr/local/sbin/zfs-auto-snapshot daily     7
14       0 * * 7 root /usr/local/sbin/zfs-auto-snapshot weekly    4
28       0 1 * * root /usr/local/sbin/zfs-auto-snapshot monthly  12