What happens when a subscription plan is suspended?

When a a subscription is suspended, all payments will stop for the period the subscription is suspended. 

When a subscription is reactivated, the payment schedule will continue as it did before the subscription was suspended. 

The payment schedule is not changed based on the amount of time the subscription has been suspended.

For example, if you were on a monthly subscription product on the 1st of January, then suspends your subscription on February 10th, you will not pay anything until you reactivate it. If you reactivate the subscription on May 20th, for example, the next payment will be charged on 1st of June, because that is the original billing date the subscription was started.