tedster - 4:09 am on Jun 23, 2012 (gmt 0)
The first site I worked with that had Panda troubles recovered within a month of making their changes live. And the recovery was to BETTER traffic than they had before. The recovery happened right after the next Panda refresh was confirmed by Google. I'll bet that, if the Panda algorithm could run in "real time" it would have recovered even faster.
I don't think "time is built into the algo", as in a rule that says "don't rank before X days have gone by." Rather, certain signals (user engagement, trust) need to be detected, and usually those things do take time to manifest stably.
I agree that recovery could take months in many cases, even with all the right changes in place. At the same time, there were several high visibility Panda cases (e.g Hubpages) that recovered a lot faster after they made changes. So there is no hard and fast rule. Given the wide variety of websites and the wide variety of Panda factors that can be in play, I guess that's to be expected.