Thank you @George4Tacks for the very helpful reply.  I did not check the CARES Act box; that might be the reason.  I notice that in the individual program, there is a critical diagnostic if this box is left unchecked.  This diagnostic was not generated in the C Corporation program. @IntuitBettyJo I wonder if it would be possible to correct the program so the transmittal letter does not mislead as to the payment date (i.e., July 15 does not appear on the letter unless the CARES Act box is checked).  Another possible solution on the user side might be to just override the payment date.  I don't envy the Lacerte programmers this year.  This has to be by far the most challenging year they've ever faced.  

@IntuitAustin what about C Corps?  Filing date, payment date, and first quarter estimate still showing April 15 even after April 1 software update.  C Corp module needs the same due date change that was finally applied to individuals yesterday.

Okay, so where is the solution?  When I click on the article, it takes me to a page that says "Accounting Help" has moved, which then begins an endless loop of clicking on the article and opening a window saying the page has moved.

@IntuitAustinhas a tip for e:filing with a payment date after 4/15, but we're still looking for a solution on entering the payment date in the first place.  Screen 3 will not currently accept an override unless the payment date is before 4/15.