Point in time recovery with mariabackup
With a full backup you can only restore to the point in time where the backup was taken.

With a incremental backup you can only restore to the point in time where the backup was taken, but you also need the full backup on which the incremental is based upon.

If you want a true point in time recovery, you have to enable the binary log (as described here). 
In a restore scenario, you would recover a full/incremental backup and then rollforward to your point in time usinge the 'mysqlbinlog' command as described here.