The event is Sunday July 19, hosted on Wikipedia Weekly Network.
Time in select zones: 1:00–3:00 pm (New York City time) 17:00–19:00 UTC/GMT 19:00–21:00 Berlin time
https://wikispore.wmflabs.org/wiki/Wikispore_Day
You can participate on the Youtube livestream here, and text chat with the presenters and ask questions, etc:
https://www.youtube.com/watch?v=q75Fv7Snc_w
I also invite you to sign up for a lightning talk, and I will be glad to send interested individuals with related topics to present the on-air link:
https://wikispore.wmflabs.org/wiki/Wikispore_Day#Interested_participants
Thanks, Richard (User:Pharos)