Is it a calendar "C" corp.
If yes, would you want to convert it as of January 1 2019, or is there a reason you would want to file a short year.
There are procedures for late elections which you could avail your self of which would bring you back to day one of the current year. . And in that way, there is no short year REV Proc 2013-30. Its not hard
Does this help ?
Abby Alhante, CPA
Kurcias & Alhante, LLC CPAs
525 Broadhollow Road Suite 104
Melville NY 11747
516.829-5890 Fax 516-829-3976
( E mail response preferred )
I have done it several times. The rev Proc lists language that must appear. In fact you will now find it as part of the 2553 PART IV on the last page.
When filing the actual 1120S, if you have not made the election and had it PREVIOUSLY BEEN ACCEPTED, we attach it to the electronic filing and check the box " 2553 attached " on the 1120S
However, to answer your original question more specifically. IMHO
I believe that without permission to change the "C" year, you would file a complete (365 dat ) "C" year, and then elect "S" . "S" would be effective day one after the "C" year. The "S" initial year would be a short period if the "C" was not a calendar.
Hope this helps, and you are welcome to call me. I will be in the office after 11..