Shouldn't count unless you're the host AND musical guest. It's not how many times you were ON the show, but hosted it...
Well, considering the genesis of the "Five Timers Club" was an actual sketch on the show that Tom Hanks hosted (and we see it a second time in the Timberlake episode), and that Paul Simon appears in both sketches, explicitly as a member, I would say it does count. Paul Simon has been the musical guest nine times. The "rules" of what does and does not count should get to be made by those who invented the concept.
And Timberlake has hosted outright 5 times; he has been the musical guest in three of those appearances. He also appeared once with N'Sync (technically making that 6 appearances).
Doesn't one of the characters in the sketch state that membership in the 5 Timers Club means you've hosted 5 times, as opposed to hosting and "guesting"?
Besides that, the hysterical feud between Steve Martin and Alec Baldwin is all about the number of times hosting the show. Number of guest appearances hasn't seemed to matter up to this point. I think that perhaps Paul Simon was in the sketch because he was in town and has been such a great friend of the show. They made a point of letting us know that Akroyd wasn't in the club and it is a fact that he has not hosted
5 times. So hosting does appear to be the significant stat.
BTW, I can't believe we're arguing what is canon in a SNL sketch.