Dan, There's no universal agreement of any time period being associated with relapse. Even Terrence Gorski, who I consider the guru of relapse, never mentions any time period associated with relapse. He merely defines it as the return to the use of any mood altering drugs. And that means anything that's mood altering, not just alcohol. If you're really intersested in the subject, read Staying Sober A Guide to Relapse Prevention someday. But whether we call it "relapse" of "slip" doesn't matter. It's something that we should focus on avoiding rather than trying to fine tune its definition.