Can I set a schedule for my clients to book, but override it when I choose to?

I’m using the Acuity trial - and I’m setting up my schedule with the hours that I allow my clients to book within.  I frequently allows other times outside of that range when booking with my personally - for long-time clients and special circumstances.  I haven’t found a way to add an appointment myself outside of the posted hours.  Have a missed a setting somewhere?