title: javascript add day to date?
body: <p>I have a string startDate, and I am trying to convert it to a date obj so I can add a day to it and get a new string &quot;2020-09-16&quot;</p>
  <p>My code below is not working though:</p>
  <pre><code>  let startDate = &quot;2020-09-15&quot;
    let startDateObj = Date.parse(startDate)
    console.log('startDateObj = ', startDateObj)
    startDateObj.setDate(startDateObj.getDate()+1);
    console.log('startDateObj = ', startDateObj)
  </code></pre>
  <p>produces output:</p>
  <pre><code>startDateObj =  1600128000000
  (node:517) UnhandledPromiseRejectionWarning: TypeError: startDateObj.getDate is not a function
  </code></pre>