title: How to use this Datepicker with Puppeteer
body: <p>I would like to crawl flight data from the following page: 
  <a href="https://www.airprishtina.com/de/" rel="nofollow noreferrer">https://www.airprishtina.com/de/</a> </p>
  
  <p>I managed to select the airports, but this page has a Datepicker and I don't get it how to use it programmatically.
  With a Click on the Startdate Input i can open the Datepicker,</p>
  
  <pre><code>await page.click('#txt_FromDateText');
  </code></pre>
  
  <p>But what do I need to do to select the date/date range ?
  I tried to wait for a day selector and click One, but this does not work. </p>
  
  <pre><code>const daySelector = '.available.flight-present';
  await page.waitForSelector(daySelector);   
  const elements = await page.$('.available');
  const el = Array.from(elements).filter(el =&gt; {
      return el.dataset.usrDate === '2019-10-26';
  })[0];
  console.log(el);
  await el.click();
  </code></pre>
  
  <p>console.log ist printing the element, but it does not get selected in the datepicker. What am I doing wrong?</p>
  
  <p>Thanks for any hints.</p>