Possible Duplicate:
How to get Modified date from file in c#
How do you, Read created / last modified time-stamp of a file, using C#?
From: http://www.csharp-examples.net/file-creation-modification-time/
// local times
DateTime creationTime = File.GetCreationTime(@"c:\file.txt");
DateTime lastWriteTime = File.GetLastWriteTime(@"c:\file.txt");
DateTime lastAccessTime = File.GetLastAccessTime(@"c:\file.txt");
// UTC times
DateTime creationTimeUtc = File.GetCreationTimeUtc(@"c:\file.txt");
DateTime lastWriteTimeUtc = File.GetLastWriteTimeUtc(@"c:\file.txt");
DateTime lastAccessTimeUtc = File.GetLastAccessTimeUtc(@"c:\file.txt");
// write file last modification time (local / UTC)
Console.WriteLine(lastWriteTime); // 9/30/2007 2:16:04 PM
Console.WriteLine(lastWriteTimeUtc); // 9/30/2007 6:16:04 PM