Cutoff days are used with fixed subscription frequencies to set a minimum amount of time that must pass between your customer's first and second order. If the second scheduled order falls within the number of cutoff days you've specified, the second order is skipped.
This prevents a subscriber's initial and second order from occurring too close together. This ensures your customer is not charged twice before they have received their first order.
Example
If your billing date is on the 1st of every month, setting your cutoff days to 15 means that all initial orders placed 15 days before the 1st, are not charged again on the next recurring date. That order is skipped.
If you need more time to fulfill your orders, you can increase the number of cutoff days.
Typically, we recommend 15 cutoff days for monthly subscriptions, but it can vary across different cases.