Targis,
Sorry. Late night answer... ringing groups wont' work like this for your system. Principle is still good though. If you are prompting the emergency DN in a CCR tree and only want to prompt at night, then have the Virtual/answer DN as a xfer path in the CCR or Menu; move your prompt anouncements to the greetings so they can be timed to present required info; then when the path is chosen as presented at night only the answer DN will ring .. but it will ring on the phones you want.
One solution anyway.
Cheers
PhM