What determines the first process date for a new subscription club?

The club member signup date determines the first process date for a new subscription club member.
When a new club member signs up for a subscription club, their first shipment will automatically process 2 days from their sign up date and all future shipments will process on the same date of the month. 
For example, if your new club member signs up on December 3rd with a 3 month frequency, their first shipment will be scheduled to process on December 5th and all other shipments following will be scheduled on the 5th of the following months.
Commerce7 - 2020-12-03T140620.648