Calendar attribute issues

When I add a calendar I am trying to use the

“Create and link to a new “More Details” page.”

but it needs Calendar Event Attribute so i go into the calendar attributes and add one. Go back to this page and nothing shows up. WHY?

I think the calendar attribute has to be a Calendar Attribute created under Pages and Themes

Ok I get it now.

You have to setup a Calendar Event attribute on the page template. Then in the output drop the block in and pull it from the attribute.

All makes sense. I knew I was on the right track but could quite see it.