Using non-UTC timezone corrupts dates imported from XML spreadsheet

[tyomitch]

This is:

• a bug report
• a feature request
• not a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

When importing an XML spreadsheet and saving it into XLSX, the dates should remain unchanged.

What is the current behavior?

The default timezone gets subtracted from all imported dates.

What are the steps to reproduce?

[root@centos PhpSpreadsheet]# cat test.xml
<?xml version="1.0" ?><?mso-application progid="Excel.Sheet"?><Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">
  <Styles>
    <Style ss:ID="date"><NumberFormat ss:Format="Short Date"/></Style>
  </Styles>
  <Worksheet ss:Name="Test"><Table>
    <Row>
      <Cell ss:StyleID="date"><Data ss:Type="DateTime">2020-05-04T00:00:00</Data></Cell>
    </Row>
  </Table></Worksheet>
</Workbook>
[root@centos PhpSpreadsheet]# php
<?php require 'vendor/autoload.php';
date_default_timezone_set('Asia/Jerusalem');
$obj = (new \PhpOffice\PhpSpreadsheet\Reader\Xml)->load('test.xml');
(new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($obj))->save('test.xlsx');

Opening test.xml in Excel shows the correct date (04/05/2020)
Opening test.xlsx in Excel shows the corrupted date (03/05/2020 21:00:00)

Which versions of PhpSpreadsheet and PHP are affected?

PHP Version 7.3.13, PhpSpreadsheet 1.13.0

The root cause of this bug is #611