title: Flutter/Dart: Convert date to yyyy-MM-dd'T'HH:mm:ss.SSS'Z'
body: <p>Trying to convert <code>DateTime.now()</code> to this: <code>2019-06-04T12:08:56.235-0700</code></p>
  <p>The API documentation insists that's Data format: <code>yyyy-MM-dd'T'HH:mm:ss.SSS'Z'</code> but I can't figure it out for Dart. Not even python for that matter.</p>
  <p>I've tried <code>now.toIso8601String()</code> but it doesn't quite nail it (i.e. <code>2019-12-03T17:50:23.476164</code>). It's missing the last <code>-</code> section and one digit. The API call within flutter returns a <code>{code:415 message HTTP 415 Unsupported Media Type}</code> as a result.</p>
  <p>What am I missing?</p>