google+crawl+date

1) get remote page

2) parse date/time 

As for the first step you can use

HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("http://...");

WebResponse response = request.GetResponse();

Stream stream = response.GetResponseStream();

StreamReader reader = new StreamReader(stream);

string htmlText = reader.ReadToEnd();

where http:// must be a query for your web site, e.g. http://webcache.googleusercontent.com/search?&q=cache%3Aasp.net

Parsing text from htmlText can be done using string functions, or by Regex.

ref:

http://forums.asp.net/t/1718810.aspx?google+crawl+date