C#：获取网络上的日期、时间

//调用方法
(DateTime.Parse(UserClass.GetNetDateTime())).ToString("yyyy-MM-dd");

public static string GetNetDateTime()
{
	WebRequest request = null;
	WebResponse response = null;
	WebHeaderCollection headerCollection = null;
	string datetime = string.Empty;
	try
	{
		request = WebRequest.Create("https://www.baidu.com");
		request.Timeout = 3000;
		request.Credentials = CredentialCache.DefaultCredentials;
		response = (WebResponse)request.GetResponse();
		headerCollection = response.Headers;
		foreach (var h in headerCollection.AllKeys)
		{
			if (h == "Date")
			{
				datetime = headerCollection[h];
			}
		}
		return datetime;
	}
	catch (Exception) 
	{ 
		return datetime; 
	}
	finally
	{
		if (request != null)
		{ 
			request.Abort(); 
		}
		if (response != null)
		{ 
			response.Close(); 
		}
		if (headerCollection != null)
		{ 
			headerCollection.Clear(); 
		}
	}
}