BobKamman
Level 15

@sjrcpa "Don't give anyone any ideas about computing the underpayment penalty through this year's due date of July 15"

It would have to be Congress getting the idea to change the law, which is easily available online. 

I.R.C. § 6654(b)(2) Period Of Underpayment — 

The period of the underpayment shall run from the due date for the installment to whichever of the following dates is the earlier—
I.R.C. § 6654(b)(2)(A)  
the 15th day of the 4th month following the close of the taxable year, or
I.R.C. § 6654(b)(2)(B)  
with respect to any portion of the underpayment, the date on which such portion is paid.