Ok
To do this we will tell the system in evening mode to ring the auto attendant which will transfer calls to a HUNT GROUP.
step 1 : Create a hunt group.
Go to hunt groups and select a free one.
Example hg01 extn 461.
set it to broadcast and enter the extns you want to be members. eg 222,223,224,225,
set them to ring only.
Step 2

pen call pilot and go to Custom call routing.
select a free ccr tree.
Example tree 2 and set it to be a HOME TRANSFER NODE.
in the section that says INTERCOM enter the hunt group extn DN that you have Created. EG: 461
While you are there check CCR tree 1 to see if its set up to transfer to Info mailbox( the one you use at night)
step 3:
Go to Auto Attendant and i am guessing the guy has used GREETING TABLE 1 .
open table 1 and in there you will see
Morn--afterrnoon--evening--Bus closed.
go to evening and set the CCR to 2 (the ccr tree you created).
set the time to 5:30
Do this all the way down for each day.mon-fri
Hopefully the Bus Closed is set to 6

m
Hopefully the Bus Closed will say CCR tree 1( night time).
NOW we go to RING GROUPS.
Remove the extns from the evening ring group and add only extn 500 which is the voicemail number.
So Now what should happen is
When evening service comes on it will ring 500.(same as Night
The voicemail will see this and route to AA(same as Night)
The AA will answer and transfer to the Hunt group.
The Hunt group will ring all the extns that you added as members.
The Hunt group will ignore forwarding to voicemail.
Have ago and try it.