title: How to subtract days in scala?
body: <p>I parsed a string to a date:</p>
  
  <pre><code>val deathTime = "2019-03-14 05:22:45"
  val dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
  val deathDate = new java.sql.Date(dateFormat.parse(deathtime).getTime)
  </code></pre>
  
  <p>Now, I want to subtract 30 days from deathDate. How to do that? I have tried</p>
  
  <pre><code>deathDate.minusDays(30)
  </code></pre>
  
  <p>It does not work.</p>