Membership Pro 2 current member renewal process

I have WishList Member installed on a client site and one feature is driving them crazy... I'd love to move them to Membership Pro 2 but need an answer before they decide. With WishList, members have to wait until their membership expires before they can renew. In Membership Pro 2 can existing members renew their membership BEFORE the expiration date? If Yes, does it create a new renewal date (e.g., one year from the date of the renewal) or will it automatically add one year to the actual expiration date? Thanks so much for your great support!