It's a good question. However, I would like to hope that for an entirely virtual conference such as this it would be decided to schedule talks at all hours. This reduces the chance of speakers, wherever they may be, from having to present in the middle of their night. Further, since every presentation will already be digital there's less extra work involved in making them all available as recordings after the fact so that "attendees" should easily be able to view all talks shortly after they finish.

If talks are spread around the clock that means less concurrency as well so your chances of being able to attend all the talks of most interest to you as they happen increase greatly.

The schedule is online at https://tpc20cic.sched.com/. You can edit the timezone on that page (by clicking on it) to match your timezone. Hopefully this reduces confusion.

There will be a stream of all the talks on Youtube if you can't/won't register with the conference services. This stream will also later be chopped up into the individual talks to make them available.

Joining the conference means booking via Eventbrite. The main chat avenue is Slack, but I'm sure that the usual YAPC irc channel at irc://irc.perl.org/#yapc (web client) and mirrored Telegram chat at https://t.me/perlcon will also be lively.