Directors earnings period commencement date clarification

I have a situation where a company was formed on 16/11/2011 when two directors were appointed. The company was dormant up to 30/6/2012. The company commenced trading on 1/7/2012 when the self employed business was transferred to the Limited Company. No remuneration has been processed up to 28/2/2013. Remuneration for both the directors is to be put through the payroll in the month of March 2013. As the directors were already appointed before 6/4/2012, I believe that the Director's earnings period commence on 6/4/2012 and not 1/7/2012 for NIC purposes. Readers clarification that my understanding is correct would be appreciated.