When we add new appointments from the appointments page and choose to send a notification to the customer, there's no way to set the customer time zone. So the customer notification shows the wrong time for any customer outside the store's time zone. And the employee notification shows the wrong time for employees who are outside the store's time zone.

So we need a way to set the customer time zone when adding appointments. And the notifications need to reflect the time zones of both the customer and the employee.