Operator queue

Got a question, right now we have our system setup that every night at 5pm a cronjob is run to set the system in to Nightmode which sends all calls that would go in to the operator queue to voicemail, at 9am it opens the operators back up.
The problem is we are under-staffed, many times I am the only person here and calls in the queue stay on hold for a long time :open_mouth:
I need something where by if the call isnt answered within X minutes it sends to a voicemail box with a message like sorry all operators are busy please leave a message…

The person I hired to setup the system is nowhere to be found :angry:
So im up the creek here :smiling_imp:

Any help would be great.

Alsoooooo, I need to change which extensions ring in the operator queue. Its not setup in the extensions.conf or voicemail.conf I think like many other things its managed in some mysql DB somewhere on the server. Any ideas on that would help also