The event is Sunday July 19, hosted on Wikipedia Weekly Network.

Starts at 1pm Eastern / 10am Pacific on Sunday, and it will run for about 2 hours.

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)