As stated in Section 2.2, you may only submit one invoice for each Delivery Period.  You will be required to invoice on or before the 10th day of the month of September, December and March and on or before the 20th day of July. All invoices are payable not later than the last Business Day of the month that follows the end of the prior Delivery Season.

If you deliver RECs in the period June 1, 2016 through August 31, 2016, then you are expected to submit your invoice no later than September 10, 2016, and the invoice becomes payable on September 30, 2016.  In your first example, if you deliver all your RECs for the first Delivery Season on June 15, 2016 and submit a corresponding invoice on the same date, then Buyer is expected to pay you by September 30, 2016.  In your second example, if you deliver all your RECs on November 15, 2016 for that Delivery Season and submit a corresponding invoice on the same date, then Buyer is expected to pay you by December 31, 2016.