title: How to set time axes labels (ticks) based on German locale
body: <p>What is the proper way to set time axes labels based a new (German) locale?</p>
  <p>I would like to use it with the vega lite API.</p>
  <p>Here is what I tried:</p>
  <pre><code>vl1 = {
    embed.vega.timeFormatLocale(locale); // show dates in German 
    embed.vega.formatLocale(locale); // show numbers with German groupings/ separators
    const plot = vl.markBar()
      .config({padding: {&quot;left&quot;: 5, &quot;top&quot;: 10, &quot;right&quot;: 50, &quot;bottom&quot;: 40}}) // now tooltip will not be clipped
      .data(cdata_lk_vl)
      .encode(
        vl.x().fieldT('Datum').axis({&quot;format&quot;: &quot;%d. %B&quot;}),
        vl.y().fieldQ('infizierte Personen'),
        vl.tooltip([ 
          {&quot;field&quot;: &quot;Datum&quot;, &quot;type&quot;: &quot;temporal&quot;, &quot;format&quot;: &quot;%d. %B&quot;}, // now date will be shown formatted
          {&quot;field&quot;: 'infizierte Personen', &quot;type&quot;: &quot;quantitative&quot;, &quot;format&quot;: &quot;,&quot;},          
          ]))
    
     return plot.render();
  }
  </code></pre>
  <ol>
  <li>I created an observable: <a href="https://observablehq.com/@ee2dev/coronavirus-in-bayern-teil-2" rel="nofollow noreferrer">https://observablehq.com/@ee2dev/coronavirus-in-bayern-teil-2</a> with the cell vl1 showing the diagram I wanted to reflect locale formats.
  Based on a suggestion from the observable forum <a href="https://talk.observablehq.com/t/changing-the-locale-for-vega-lite/3010" rel="nofollow noreferrer">https://talk.observablehq.com/t/changing-the-locale-for-vega-lite/3010</a> I implement this:</li>
  </ol>
  <p>This seems to work - sometimes !?. Over the last two months, there were days as today, when the format is switched back to the default US_EN</p>
  <p><a href="https://i.stack.imgur.com/rUPmW.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rUPmW.jpg" alt="enter image description here" /></a></p>
  <ol start="2">
  <li>The related question here <a href="https://stackoverflow.com/questions/61657984/how-to-set-locale-to-show-time-with-my-language/61660831#61660831">How to set locale to show time with my language?</a> doesn't seem to help in this case</li>
  </ol>
  <p>I would really like to know, a) what is the proper way to do it and b) why does my solution sometimes work other times not (without me changing the code)</p>