Albacore/Longfin Tuna?

[Chico]

I have read that the longfin show up later in the season, after the yellowfin. If this is true, about when do they usually start showing up?? Last year I had my first yellowfin in the first week or Oct. If I remember right, it was within a week or two, that they started catching the longfin as well. I have a mahi/tuna trip in mid sept, and am looking for another date that might give me a shot at longfin as well.