Every month we have a lot of reports and questions about mid-month additions and changes in the Google index. Last month we started consolidating them into one thread so all the information would be easier to find and be especially helpful to those new to Google or our Google News forum.
You can refer to September's Everflux / mid-month changes [webmasterworld.com] to see the previous pattern, which is one of the primary reasons we're trying to keep them all together.
1.The Monthly Update
There's one major Google update per month, starting somewhere between the 20th and the 28th. It generally takes several days to settle, at which time the data migrates to Google's partner sites.
2. The Monthly Crawl
The major crawl takes place at right around this time. With some it's been reported to start at the same time or just before the update begins, while others are not crawled until afterward. This continues for several days, and there's been some conjecture that PR might possibly have something to do with the timing.
3. Mid-month activity, referred to as Everflux.
All during the month between updates there has been some spidering, sites added, and minor position changes. This is related to Google keeping their search results "minty fresh" but while minor ranking changes occur, this does not affect the entire index.
It's worked well, so we'll continue to do this now, in October. This is where we can post what we experience and observe, to compare and discuss it among ourselves. We'll again confine it all to one thread so it's simpler to keep track of the information and observations we share that are so important to us all.
Note: We'll be moving some threads onto this one, as we did last month, as well as for the update itself.
We sincerely thank you for your contributions to our collective knowledge and understanding and wish you all good luck with your sites.