Set retirment date in dialog for a service

Hi I want to retire an service on a specific date and want to set this in the dialog. How shoud I name the item?

You already have “Set retirement date” button for services.

When I’ve done this before, I set the retirement date of the service in a post provisioning method. I think you can only set the retirement date of VMs with the dialog variables with the use of something like option_1_retires_on.