title: Date format changing when converting xlsx to json
body: <p>I am trying to read data form xlsx file and converting it into json, but the date column value is changing
  Here is the screenshot:<a href="https://i.stack.imgur.com/imdtZ.png" rel="nofollow noreferrer">Screenshot of my excel file from which i am reading data</a></p>
  <p>Here is the code for reading data from excel file and converting into JSON:</p>
  <pre><code>onBasicUpload(event){
  let workBook = null;
  let jsonData = null;
  const reader = new FileReader();
  const file = event.files[0];
  console.log(file,&quot;file is here&quot;);
  
  reader.onload = (event) =&gt; {
    const data = reader.result;
    workBook = xlsx.read(data, { type: 'binary' });
    jsonData = workBook.SheetNames.reduce((initial, name) =&gt; {
      const sheet = workBook.Sheets[name];
      initial[name] = xlsx.utils.sheet_to_json(sheet);
      console.log(jsonData,&quot;jsonDAta&quot;);
      
      return initial;
    }, {});
    const dataString = JSON.stringify(jsonData);
    console.log(dataString,&quot;stringify data&quot;);
    this.jsonArr = JSON.parse(dataString)
    console.log(this.jsonArr,&quot;parsed json&quot;);
    console.log(Object.keys(this.jsonArr['data'][0]))
    
  }
  reader.readAsBinaryString(file);
  }
  </code></pre>
  <p>It is returning me this:
  DOCDT is the value of the date being returned.
  <strong>{&quot;data&quot;:[{&quot;DOCNO&quot;:&quot;001&quot;,&quot;NETAMOUNT&quot;:30000,&quot;IREF1&quot;:&quot;50&quot;,&quot;IREF2&quot;:&quot;100&quot;,&quot;DOCDT&quot;:43989},{&quot;DOCNO&quot;:2,&quot;NETAMOUNT&quot;:40000,&quot;IREF1&quot;:40,&quot;IREF2&quot;:90,&quot;DOCDT&quot;:43989}]}</strong></p>