Adjust date and time function using date header from HTTP response for NETMF.

AdjustDateTime.cs

    private static bool AdjustDateTime()
    {
      try
      {
        var webReq = WebRequest.Create("http://time.windows.com");
        webReq.Method = "HEAD";
        var webResp = webReq.GetResponse();
        Debug.Print("Begin Response.");
        foreach (var key in webResp.Headers.AllKeys)
        {
          Debug.Print(key + ":" + webResp.Headers[key]);
        }
        Debug.Print("End Response.");
        // Example) Tue, 24 Mar 2015 23:59:14 GMT
        string dateStr = webResp.Headers["Date"];
        webResp.Close();

        string[] dateElements = dateStr.Split(new char[] { ' ' });

        string tz = dateElements[5];
        if (tz != "GMT")
        {
          throw new Exception("Date string is not GMT.");
        }
        int day = System.Convert.ToInt32(dateElements[1]);
        int year = System.Convert.ToInt32(dateElements[3]);

        var monthStrs = new string[] {
          "Jan","Feb","Mar","Apr",
          "May","Jun","Jul","Aug",
          "Sep","Oct","Nov","Dec"
        };
        int month = Array.IndexOf(monthStrs, dateElements[2]);
        if (month == -1)
        {
          throw new Exception("Date string cannot be converted.");
        }
        month++;

        var timeElements = dateElements[4].Split(new char[] { ':' });
        int hour = System.Convert.ToInt32(timeElements[0]);
        int minute = System.Convert.ToInt32(timeElements[1]);
        int second = System.Convert.ToInt32(timeElements[2]);

        var dateTime = new DateTime(year, month, day, hour, minute, second);
        Microsoft.SPOT.Hardware.Utility.SetLocalTime(dateTime);
      }
      catch (Exception exc)
      {
        Debug.Print("Failed to adjust date. " + exc.Message);
        return false;
      }
      return true;
    }