Yes, there are few ways to achieve it.
First of all when you say calls are routed to agents during business hours, do you have contact center solution i..e UCCX? If so then the easiest way would be to do the time of day check there.
If you do not, then CUCM does have time of day routing capabilities with time periods, time schedules that get assigned to partitions. So, you could create a time period for 5-10PM, assign it to time schedule, built new partition and assign the schedule there. Then you can build a CTI Route point with a DN that matches the number of your normal day number already in use, but assign it to the new partition. Lastly, you need to ensure this partition is listed above the other partition (normal routing) in every Calling Search Space that a call is initiated from, i.e. ingress GW/trunk, phones, etc.
