Discount Family Subscriptions!

[user-removed]

On the Q&A Page for Premium Family, it mentions that if I have an existing Premium account, "any remaining time that you've already paid for will be converted into a Premium for Family subscription, so this can bring your next payment date forward".

Could someone explain this to me a little more?

I have a premium subscription till April 1, which I got through a promotion and I would like to make the most out of it, when starting a family plan.