You might get a reply quick. But the EFFECT is often only seen with the next Penguin update - and those are about every 4 months.
This isn't cast iron, some recover more quickly (I suspect Google had a manual look - or discovered the opposition was even worse) but of the several I've done - they tend to refloat (if they do at all) after the next Penguin update. I'm guessing January/February for the next one.
Also depends on whether you've just been demoted a bit - otr had the dreaded "un-natural linking notice" and/or sandbox. If that's the case then think 3-4 months no matter what. A demotion is normally algorithmic. A tidy up might qork quite quickly. Recovering from an ULN or sandbox..i've never heard of that taking less than 3 months, but sites do recover if the webmaster bows on bended knee to Google.
Which - if it was a negative SEO attack that got you their in the first place, then grovveling to Google is just adding insult to fucking injury. Like being kicked in the nuts and having to say sorry to the guy that did it to you.
Scritty