title: Prometheus timestamps
body: <p>I wrote an exporter which exposes timestamp next to the metric like:</p>
  
  <pre><code>test_load_min{app="web01"} 1 1483228810000
  test_load_min{app="db01"} 2 1483228820000
  test_load_min{app="email01"} 3 1483228830000
  </code></pre>
  
  <p>According to <a href="https://prometheus.io/docs/instrumenting/exposition_formats/" rel="noreferrer">https://prometheus.io/docs/instrumenting/exposition_formats/</a> this should be fine for Prometheus, but querying test_load_min in Prometheus UI returns empty result. Same without timestamps works fine. Anyone has an idea what's wrong there?</p>