title: Azure Data Factory Convert Date to YYYYMMDD then to String
body: <p>I'm new to data factory so please bear with me.</p>
  <p>I have files names coming in via metadata activity and I need to filter on all files that contain in the filename todays data in format YYYYMMDD</p>
  <p>File format example: <code>DailyStock20200914.csv</code></p>
  <p>In my filter I have a <code>@contains(item().name, '20200914')</code> which works.</p>
  <p>I want to add an expression something like</p>
  <pre><code>@contains(item().name, toString(toDate(utcnow(),'YYYYMMDD')))
  </code></pre>
  <p>but can't workout the date part and can't track down the answer on the internet.</p>