The SAP CAL license is listed as 'Appliance per Month'...
My question: If I create an appliance on the 5th of the month... unlock it... use it for 6 weeks (now in the 2nd month), and complete my testing; remove the appliance - when can I create a new appliance?
Is this one ACTIVE appliance at a time?
Your SAP CAL Subscription quota is for the number of X instances that are active at the same time. You can even mix and match the different solutions within a subscription period if the number of active instances at any given time does not exceed the number covered by your subscriptions.
For example, if you have quota for 1 instance, you can have only 1 instance in Active state and your other instances must be kept suspended at that time. If you need to work with another of your instances, you can suspend the first one, and activate the other.
This is applicable for all used by you instances beyond their free trial period.