Comment 1 for bug 400459

I believe the length it uses is '1 day or the next time the user logs in, whichever is sooner'.

I can see why this should be clearer and/or allow the choice of a time delay. I think most users really just want a 'don't bother me right this second, but I do want to backup' button, which is what I tried to provide. I'll have to think about the right behavior/UI here.