title: How to plot int to datetime on x axis using seaborn?
body: <p>I am trying to use seaborn to plot a graph</p>
  <pre><code>sns.lmplot(x=&quot;when_start&quot;, y=&quot;how_long&quot;,hue= 'state',
             data=apps_pd.loc[(apps_pd['user'] == 'xavi')],lowess=True);
  </code></pre>
  <p>Where <em><strong>apps_pd</strong></em> is a dataframe. And fileds in <em><strong>apps_pd['when_start']</strong></em> are int like 1499963856220, and same for <em><strong>how_long</strong></em>.</p>
  <p>Result of the script</p>
  <p><img src="https://i.stack.imgur.com/1TteZ.png" alt="" /></p>
  <p>However, I got a really messy graph if I don't change the format of the data.</p>
  <p>Is there anyway I could change the unit of x-axis to 'yyyy-mm-dd'? I want to group all my data in day level.</p>
  <p>And also could I change the unit of y-axis to hour-min-second?</p>
  <p>Here is the first 5 lines of my dataframe.
  <img src="https://i.stack.imgur.com/uoMmU.png" alt="" /></p>