Selling plans can now specify a fixed cutoff day for a delivery policy

As of GraphQL Admin API version 2022-07, the SellingPlanAnchorInput type has an additional optional field.

cutoff_day represents a fixed cutoff day for each anchor, to be used for monthly and weekly selling plans. Use this method if the cutoff should land on the same day each month.

You can also specify a cutoff using the cutoff field of the SellingPlanRecurringDeliveryPolicyInput type, which represents a duration. Using cutoff, the exact cutoff day could be different based on the number of days in the month.