Write SQL query to solve given problem: What was David Rubin's job in the movie "Days of Thunder"?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.job FROM movie AS T1 INNER JOIN movie_crew AS T2 ON T1.movie_id = T2.movie_id INNER JOIN person AS T3 ON T2.person_id = T3.person_id WHERE T3.person_name = 'David Rubin' AND T1.title = 'Days of Thunder'