Set the System Schedule Business Hours (basically uncheck time blocks when business is closed)
Check the result (you can add holidays on the third tab on your own as well...
Now select the night Bell Phones (purple)- I selected 4 stations.
Set the NS Activation toggle code (*499 in my case) for when you need to invoke it on the fly (override schedule)
It was found that since CCA now pushes a Telephony-Service FAC down to the UC 500, which includes *4, you should use a code that is not a FAC *code or NS will not toggle when you enter the code. Do a 'show telephony-service fac' to see codes you can use. Based on this output, it appears the only codes that will not conflict with other fac must start with *2, *7, *8, or *9.
Select the extensions for which NS treatment will apply. 202 is associated with a SIP Trunk DID.
Select the treatment you want (you can forward to your cell, or another timezone location; you can ring the NS stations.
Do a CLI command (show clock) on the UC520 and verify the time on the phones matches. If NS is active, the NS Active display shows on phones
Now you can toggle it (enable/disable) from 202 or 203 using The CODE You Defined above
Thats it, this worked in my lab. One forwarded out, the other rings the night bell.
Night Bell phones alert and display "Night Service 202" so you can use call piackup to pick up the call from those locations.