We have a revenue schedule for when a subscription is paid for (e.g. for a period Mar 10 - Apr 10) and it should be immutable, so the revenue is recognized across that period only. Less is recognized only in case there is a refund issued.
In case the user's subscription enters a grace period Apr 10 - May 5 due to a payment failure upon the subscription renewal, as there is no payment, no revenue is recognized as well as no amount needs to be taken back either.
More information about the Revenue recognition reports is available here and here.