title: HttpWebResponse LastModified
body: <p>Is the HttpWebResponse.LastModified accurate? Is it always present? My project is to create a sort of a focused web crawler and I am stucked if I will use the hash value of a resource or just the HttpWebResponse.LastModified property to check the resource's "freshness".</p>
  
  <p>Using the hash value means streaming the resource every time it's checked. This has a big impact on overall performance.</p>
  
  <p>If I will just check the HttpWebResponse.LastModified, is it accurate?</p>