12 pm. The time zone difference from New York to California is 3 hours. If you get on the plane in New York at 9, you're practically getting on at 6 in California's time. So if the trip takes 6 hours, then if you basically got on the plane at 6am (again, going by the time it would be in California, not New York), then add 6 hours to 6am, and you get 12pm/noon.
Hope I helped!