I wanted to create a single duplicate of an event in the Microsoft Outlook (for Mac) calendar and I couldn't find out how to do that. Copy and paste? Didn't work. Maybe there is a function in the menu bar? Yes, there is, but it's deactivated for calendar entries.
Maybe there is an entry in the context menu? Nope.
Then I thought about how I usually duplicate objects in design applications: by dragging them while pressing the alt key.
And that's actually how you copy calendar events in Outlook!