How to clear pending appointments?

We have some clients with over a hundred "pending appointments" stretching back two years or more!

Is there some way to mass remove these? Manually selecting them one by one and clicking delete is just way too repetitive.

Unfortunately there is no option to remove all pending appointments at once. You should delete them or mark as done (recommended) manually.

To speed up the process you can use 'Done' button located at the bottom of the Account Pending tab. Once done, the appointment will be removed from the Pending tab and will stay in Calendar.

Hope this helps.

Could you look into implementing a multiselect feature so more than one can be deleted at a time. I have just found that our engineers have tasks/appointments dating back to 2012 and now I have to delete them manually :(

Sure, noted and will be considered for a future release. Thank you.