You are thinking of *new* IRA *contributions* that can be made for the previous tax year up until the due date of that tax years tax return - April 18, 2017 for the 2016 tax year. That has nothing to do with rollovers or conversions that cannot be retroactive.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
