Done (see the calendar now):
- noGLAMorɚ - CSOs in culture (hybrid workshop on Wikidata+Wikispore+… practice)
- #notNewNORMAL [Call for contributions] workshop & practice
I’m learning myself as we speak. 
Only users who can edit the description can make this change. This means that this is either the author, moderatos/admins… or we can convert the post in a wiki post and then anyone can do it. I’ll do this for this post.
Then you need to edit the post, place the cursor at the top of the post, click the 
icon, and click “Create event”. A form will appear, fill it, and save changes. This should work.