Which time zone is the calendar in?

Yours. Slots are shown in your browser’s own zone, and your confirmation email is written in the same zone you booked in.

From the guide Booking a Call About Custom Pricing.

Your calendar

The confirmation email carries a calendar invitation, so the call lands in Outlook, Google Calendar, Apple Calendar or anything else that reads a standard invite — with the join link on the entry itself. There is an “Add to calendar” button on the confirmation screen too, for when you book on one machine and keep your calendar on another. Anything that happens afterwards — a move, a cancellation — updates that same entry rather than adding a second one.

Read the whole guide: Booking a Call About Custom Pricing

More questions about Booking a Call About Custom Pricing

• How do I know my camera and microphone will work?
• Are the captions private?
• Do I need an account to join?
• What if nobody lets me in?
• Is the call recorded by default?
• Where does the video go?
• Will it be in my calendar?
• Can I move the call instead of cancelling?
• Nothing is available in the calendar — what now?