Can you try to check this post below someone asking the same thing and maybe it will work?
Would these cgminer commands work on an S9 running Braiins OS?
How would I set them? edit a file with terminal?
--sched-start Set a time of day in HH:MM to start mining (a once off without a stop time)
--sched-stop Set a time of day in HH:MM to stop mining (will quit without a start time)
Probably
/etc/cgminer.conf
{(the_rest_of_the_options)
,"sched-start":"07:00","sched-stop":"18:00"}Don't forget to restart cgminer with
/etc/init.d/cgminer reloadThe only problem he is using Braiins OS but maybe it will also work on default s9 firmware. Just try