With the Bookings API the customer can book in any timezone. The timezone on the booking is always the timezone of the location the booking is created at and to get the timezone of the location you’ll need to call the Locations API. 
With the Bookings API the customer can book in any timezone. The timezone on the booking is always the timezone of the location the booking is created at and to get the timezone of the location you’ll need to call the Locations API.