On call virtual assistant

READ BEFORE BIDDING PLEASE!!! I need a virtual assistant who can return calls between 4:30pm EST-8amEST Monday through Friday then weekends. This would be on call, and typically between 1-8 calls daily. The calls could consist of clients cancelling shifts or employees calling off a shift and re-staffing the shift. You would receive a notification that a call came in and then check the voicemail. Based on the call, you would then react to scheduling. We prefer a base weekly rate for being on call then hourly for the time spent handling the call.