Earlier today I (stupidly) compromised two of my most important socks. I normally edit with one of them via a VPN link which gives an IP address in a different country - but I forgot to log into the VPN link, hence both socks now have the same ip address. It probably won't get picked up, and I'm thinking of leaving both sock accounts for now, so that no futher suspicions are raised - but for how long? Can someone remind me how long ip data for an account is now held? I had heard five months

It used to be 6, but I think it's 3 now.

They say 3 months. However, I'm sure there are some zealots among the CheckUsers who keep their own personal copies of CU data indefinitely.

The only data they can keep that way is what they get from an actual check or log of someone else's check.

Checkusers keeping personal records does enable some forms of stupidity, like blocking entire towns to stop one person, but it also allows identification of editors like Mantanmoreland. So "zealotry" is, as with everything else, in the eye of the beholder. (One form of stupidity that WR is susceptible to is "admins/CUs are stupid/incompetent/abusive because they blocked X" uttered by the same person who complains "admins/CUs are stupid/incompetent/abusive because they didn't block Y.")

The duration of the checkuser table is set by a variable in the Mediawiki software that is apparently publicly viewable if you know where to look; it is currently 90 days. A couple of years ago, one of the developers -- who was also a checkuser -- increased it to 5 months, and he got reverted and publicly slapped by another developer. So the stupid and abusive ways Wikipedians treat each other is not confined to the lower decks.

Back to the original question, if you can go 90 days without raising suspicion, you are reasonably safe, because even saved checks have their limits -- and that's assuming your account(s) have been checked before, which they probably weren't unless someone has been complaining about your behavior.

Thanks for the info folks. Three months is do-able. I'll re-activate a couple more socks over the next two weeks that have been sleeping for a while now.