Wow, I'm so sorry. I thought I had included that with my other posts, but it's a pretty straightforward formula for ban lengths.
Fourth offense would be a month long ban!
To make up for missing this information the first go around, I've made it into a little poem as a challenge.
First offense allots a single day,
the second will be three.
Third becomes a week, next a month,
then they're banned perma-nen-tly. (NOTE: NOT ANYMORE)
I know that was terrible, so here it is in a more standard layout.
1 day
3 days
1 week
1 month
I hope that clears that up!
EDIT: Jeez, I almost forgot you guys took away permanent lengths for non-serious (hacking/illegal) things, so this should be the formula.