Use LastModified
/* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852 */ // Use LastModified. using System; using System.Net; public class HeaderDemo12 { public static void Main() { HttpWebRequest req = (HttpWebRequest) WebRequest.Create("http://www.Microsoft.com"); HttpWebResponse resp = (HttpWebResponse) req.GetResponse(); Console.WriteLine("Last modified: " + resp.LastModified); resp.Close(); } }