Not sure exactly when my file was complete at USC but since I'm an August MCATer I'm thinking it was complete around mid October. I got the email invite for an interview last Thursday.
When I chose an interview date all the days were in Dec were already full(except dec 11th which I chose), so they are already into Jan for interviews.
As for Loma Linda I haven't heard from them this year. However, I received an interview invite from them last year in early January and my files were also complete around mid october last year. Are you SDA? I've heard that Loma Linda interviews SDAs first then non-SDAs later. Based upon the non-SDA people I knew who interviewed there last year there may be some truth to this rumor.
Hope that helps!
Good luck!