title: How to create timestamp in seconds
body: <p>I have this task to populate this field:</p>
  
  <blockquote>
    <p>x_fp_timestamp is the timestamp created when the form is generated. It
    is equal to the number of seconds since January 1, 1970 in UTC
    (Coordinated Universal Time).</p>
  </blockquote>
  
  <p>So what I do in C# is</p>
  
  <pre><code> long ts =  DateTime.Now.Ticks / TimeSpan.TicksPerSecond;
  </code></pre>
  
  <p>But in that case I am getting this error:</p>
  
  <blockquote>
    <ul>
    <li>x_fp_timestamp : x_fp_timestamp invalid. Not within 15 minutes of
    present time: Thu Jan 10 21:30:25 GMT 2013. Expected 1357853425
    plus/minus 900, but received 63493442997.</li>
    </ul>
  </blockquote>
  
  <p>So my question is how to generate current timestamp in seconds?</p>