I think the question may be can I send the call to the receptionist during business hours and to an IVR outside of business hours? If that is the question, then "Yes" you can define this in your inbound rules. If the question is can I sometimes route the call to an IVR and at other times route the call to the receptionist, the answer is a qualified "yes". You could route all calls during business hours to the receptionist, and configure the receptionist's extension to route to the IVR when the receptionist's presence is set to "Away". There are lots of strategies for doing this, you just have to figure out what works best for your situation. We need a little more information to provide a more definitive answer.