Anyway, about Matt's post, he says:
"The shortest time frame used to be something like three months; now you can look for things that are less than 24 hours old. What GoogleOS noticed is that the advanced date search affects a url parameter called Ă˘â‚¬Ĺ“as_qdrĂ˘â‚¬Âť and Chitu figured out some of the possible values:
The nice thing is that you can change the value of as_qdr to custom intervals. Here are all the possible values of the as_qdr parameter:
- d[number] – past number of days (e.g.: d10)
- w[number] – past number of weeks
- y[number] – past number of years
This little tweak is as handy as Ă˘â‚¬Ĺ“&strip=1Ă˘â‚¬Âł on cache: queries and Ă˘â‚¬Ĺ“&filter=0Ă˘â‚¬Âł on site: queries. Why? ItĂ˘â‚¬â„˘s an easy way to see new urls that Google has just discovered in the last few days.
For example, thereĂ˘â‚¬â„˘s been a lot of fast progress on iphone stuff recently. A query such as http://www.google.com/search?q=iphone+source+code&as_qdr=d1 would show all the new urls for the query [iphone source code] within the last day, because d1 stands for 1 day.
Suppose you wanted to see all the new urls that Google found on your site within the last 7 days. For the domain mattcutts.com, IĂ˘â‚¬â„˘d use a query such as http://www.google.com/search?q=site:mattcutts.com&as_qdr=d7 to find those urls (remember, Ă˘â‚¬Ĺ“dĂ˘â‚¬Âť stands for days and Ă˘â‚¬Ĺ“7Ă˘â‚¬Âł stands for, well, 7). Previously, you could check whether Google had indexed a new url by (say) searching for content from that url, so this isnĂ˘â‚¬â„˘t completely new, but it still simplifies life for site owners."
For more, read Useful Google feature: better date search.