Here's my opinion:
If you're going to use about to help describe the purpose of a noun, then that noun has to be something with content that can be understood.
That book is about dogs. That play is about divorce. That meeting was about new construction.
If you're using about to mean almost or approximately, then that is an entirely different matter.
That book is about two inches thick. That play is about three hours long. That meeting is about over. That occasion is about four days away.
That occasion was a birthday party for my grandson.
That occasion was about five months ago.