He fasted the day of ‘Arafah with the intention of making up a day from Ramadaan
Question

                I fasted on the ninth of Dhu’l-Hijjah, the day of ‘Arafah, and I intended that fast to make up for a day of Ramadaan. Does fasting the day of ‘Arafah count if I intended it to make up for a missed Ramadaan fast or not?.
Praise be to Allah.It is permissible to fast on the day of ‘Arafah to make up for a missed Ramadaan fast, if one intends it to make up that fast. 
And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote. 
Standing Committee for Academic Research and Issuing Fatwas