The automatic bill payment process 2-3 days prior to the end date of the subscription. This is to allow us to reprocess payment on the second day in case there's an issue with the 1st payment run.
This is also to avoid inconvenience to our users when the payment did not proceed and they lost their subscription. However, rest assured that it might be 2 days early, the subscription date still ends on the same day. You may check it here.