title: How to get unixtime with typescript
body: <p>I tried below.</p>
  
  <p><code>var unixtime = new Date / 1000;</code></p>
  
  <p>then, compilation error occured.</p>
  
  <p><code>error TS2113: The left-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type.</code></p>
  
  <p>How to get unixtime with no compilation error ?</p>