Hi, is it possible to copy an appointment from one day to another?

In the calendar, hold down your control key and click and drag to the new date/time. This is the easiest way to create a copy. If you only want to move it simply click and drag.

Craig Holmes you are a magician - thank you

Craig, you made my life a little easier.

When I hold the Control Key and click on an appointment, that appointment gets highlighted ... but that's it. I can't drag it anywhere. What am I doing wrong?

You want to first click on the appointment, don't open it, just hold your left mouse button down. While doing that, hold down the Ctrl key and drag to the new appointment location.