A few weeks I'd guess.
That'd be for holidays, or extended downtime waiting for repairs for my old laptop.
When I was on holiday it didn't bother me, when waiting for repairs I got really frustrated because it took so long.
Even when I was a kid on our old family computers I'd use it once every week or so.
Now though I use it every day unless something happens, like I go out or there's a power cut or something like that.