Events other than onactive / onhold / onexpire etc

Dear Stackideas,

While developing an app, how do we take into consideration "Renewal" that a customer does before expiration... In this case, the subscription is already active, there is no expiration yet and only the expiration date has moved up.

Is there an event that we can check for in our code, that whenever a person "renews" before expiration, we do x y or z

Thanks