I'm on and off, so it's hard to say how long I go -without- it. I don't think there has been a period where I have decided to quit fully (since, like most people who try, they're usually drawn back further down the road).
I'm much of the same way as S.N.N. actually, as most often I just takes breaks from it. I don't quit it entirely, I only have relatively long periods of withdrawing from it. If I remember correctly, I think the longest period of withdrawal was maybe three months or so. Then again I have a feeling that's a little exaggerated.
I also go on and off on SMW hacking. When i don't feel like doing anything smw hacking related stuff i just take a break until i feel like hacking again. hmm, i think my longest break from smw hacking was 5 months or so due to me having to focus on real life.
I've tried to open Lunar Magic a bit about a month or so ago, but every time I open it, I close it and then open Minecraft instead. I don't hack as much. Even if I do hack, I would only be able to once a week or so, because my windows computer at home is horribly laggy and the only fast computer at my house is my mac.
During all the time that I've actually spent on the site, I have been working on a SMW hack of some kind.
However if you mean lengths of time without actually working on a hack, then usually the longest breaks I take span about a month or two, usually after having released a demo, or flat out losing inspiration (or both).
I suppose you could say I hack SMW passively, whenever I feel like there isn't anything else I want to do or when I have an idea. On average I probably spend about a couple of hours a week working on levels and such, but on some days I spent entire mornings/nights on it.
-------------------- May we meet again outside the battlefield.
Its been about 5 months now. Gonna try to get back to it this week hopefully. Since its spring break right now and have more time I will probably have nothing else to do at one point except open Lunar Magic.
The only time I was really on a break (from hacking as well as SMWC) was from March-July last year. I was just too tired of hacking and other things had gotten more priority leaving less time for hacking and stuff. When I regained interest, I asked SNN if I could be on the staff team again but it wasn't until January that I started to work on a hack. Progress on it is going pretty slow and I only open LM a few times in a week.
When i don't feel like doing anything smw hacking related stuff i just take a break until i feel like hacking again.
I generally only work on levels when something is going on (collab projects, SMWC contests, helping a friend with something).
The last level I worked on was my Winter Contest level, which wasn't finished due to me being too busy. I'm going to try to revive it for the next Chocolate Contest though, because I did spend a good amount of time on it and would hate to see it go to waste.