title: Plotly Express timeline for Gantt Chart with integer xaxis?
body: <p>I'm using plotly express timeline to produce a Gantt chart following this example: <a href="https://medium.com/dev-genius/gantt-charts-in-python-with-plotly-e7213f932f1e" rel="noreferrer">https://medium.com/dev-genius/gantt-charts-in-python-with-plotly-e7213f932f1e</a></p>
  <p>It automatically sets the x-axis to use dates but I'd actually like to just use integers (i.e. Project Kick-Off +1, Project Kick-Off +6, etc).</p>
  <p>Is there a way to make a timeline plot NOT use dates for the xaxis?</p>
  <p>If I try using integers it'll treat them like milliseconds.</p>