title: Convert Binance timestamp into valid datetime
body: <p>I dont know how to covert timestamp given by Binance server into valid <code>DateTime</code>.</p>
  <p><code>Binance.API.Csharp.Client.Models.General.ServerInfo</code> returns
  <code>1615724572987</code> which after conversion to <code>DateTime</code> gives
  <code>1/2/0001 9:52:52 PM</code>
  which obviously is not correct.</p>
  <p>I tried to find description about ServerInfo type but there is only GetHtml Function.</p>