I thnk a DANCE and an UPDATE are two different things... but -- I've noticed my rankings stay the same for the last few days. I was wondering -- how often should I expect them to significantly change? is it 4x a month? How often do they change their algo? I saw a significant change on the 31st of Oct.. (it wasn't a good one for me)
The very reason why it's called Google Dance is that no one knows exactly when. It "dances" The recent changes didn't give a good result to me also..
Earlier (4-5 years ago), the dances used to happen once every quarter then every month. I think now the dances happen almost every day. I see up and down movement for some of my new sites everyday.
page rank changes every 3 to 4 month however the google dance goes on daily for new websites. Only websites with authority tend to stick.
This is about right - if you are talking PR update it seems to vary from 2-4 months, usually around every quarter (as has also been mentioned above).
If you are using Webmaster Tools, you will see your "external link count" start to change. This is what they call "BL" update (back link). Once this is done, they can do the new PR calculations.
4 or 5 years ago "The Google Dance" was a term that indicated that google was updating its search results and there would be wide swings in SERP for several days while all the new data centers were updated. Basically, If you were #1 for blue widgets, you would stay that way for about a month or so until the next google dance would occur. You would not see immediate results when new links were added. Now, Google continually updates the SERPs and there are no world-wide, massive fluctuations in SERPs that take place over 3 to 5 days. The dance really no longer exists like it did 4 years ago. Google does tweek its algo, and that happens whenever they want.
The dance is happening every second of ever minute of every day. Google is consistently crawling and updating sites in real time.