From the Crunchy Data event page:
Crunchy Data is excited to announce that we’re hosting the 4th annual PostGIS Day November 17th! We had such great conference participation last year around the globe that we are doing it again. The conference is in a virtual drop-in format.
Every year on the Thursday of the third week of November, we celebrate our favourite spatial database.
Read more at https://postgisday.rocks/