Setting up an SL2100 for day night switching. I can flip between day and night mode. Night mode answer instantly but plays day greeting. Checked a couple of databases on customers using seperate greetings but unable to find anything. Thanks.

Need to know if analog, PRI or SIP trunks.

If you want the Night button to trigger a NIGHT greeting I believe you point the trunks to a virtual extension in NIGHT mode, the virtual is call forwarded always to 3999 and that virtual triggers a routing mailbox which will be your night greeting.

You would point calls to a virtual if you have PRI or SIP trunks for day mode, night mode calls are pointed to the voice mail pilot 3999.
Analog trunks you would DIL in night mode to 3999

You can setup manual night to play the night greeting when pressed. You can even set it up where you can call in from the outside to change the greeting.