NeetoCal lets you decide whether clients can cancel or reschedule their meetings, with a separate policy for each scheduling link. When cancellation and rescheduling are allowed, the confirmation email includes links the client can use to cancel or pick a new date and time.
Set this up from the Cancellation and Rescheduling card in the link's Settings tab. If the meeting is paid, you also get refund options for cancellations. These rules apply only to clients. As the host, you can still move or cancel any meeting when needed. If a client or host declines or deletes the event in Google or Outlook Calendar, NeetoCal marks the booking as canceled too, which keeps both records in sync.