Not every sunset is a wonderful as the one shown in the headline graphic of this article. As if you were not already expecting it, after May 31, 2018, access to Intuit add-on services will be discontinued for all QuickBooks 2015 Desktop products.
This year's sunset policy includes all versions of QuickBooks 2015 (Pro, Premier, Enterprise, Accountant, and Mac). While these discontinued products will continue to work, you will not be able to subscribe to live technical support or any of the other Intuit services that you could previously integrate with your 2015 QuickBooks software including Desktop Payroll services, Online Backup, Online Banking and others.
The following table, courtesy of Intuit, illustrates their Calendar Year 2018 Discontinuation Policy regarding QuickBooks 2015 Desktop products.
Intuit
Intuit QBDT 2018 Sunset Policy
For more information regarding Intuit's 2018 QuickBooks Desktop service discontinuation policy see their official website.