second
(I knew a guy like that. You could ask him what the first, second, third or fourth Sunday was of any month of any year and he always got the number right. Sometimes he got it quick and sometimes it took a few seconds. We tested him a lot because he loved doing it and he never missed. He only did Sundays though. He was in his mid 20s at the time and was about at a 5 year old level with intelligence. It was amazing to witness!)