Manage Time in Subscription Purchase - iOS

For my app, I want to provide Subscription based In App Purchase feature. So I have created a product at Apple Store - Non-Renewing Subscription.

But in that product creation, I didn't specify any time up to which time this subscription remain valid, for ex. Monthly or Weekly Subscription days limit.

So from app I can manage Subscription purchase related thing but how to get information about expiry of Subscription? So that I can show again Subscription dialog to make purchase...

Manage Time in Subscription Purchase - iOS