1) Access the Calendar from your Gmail account
2) Click on the timeslot you have the appointment, and click “Appointment slots”. You will also have the choice to review specific options (duration, date, time, calendar) and fill them out as desired. Once finished, you can either Save or go to "More options" to customize the slots further.
For further information, please see Google's article at:
Last Updated: 02/17/2020