Dear Olivier Mercier,
1. please go to your_site\templates\sj_health\html\layouts\joomla\content\info_block\publish_date.php and find:
$full_date = JHtml::_('date',$displayData['item']->publish_up, JText::_('DATE_FORMAT_LC4'));
=>
$full_date = date_format(date_create($displayData['item']->publish_up),'Y-m-d');
2. Date in article detail: go to your_site\templates\sj_health\html\com_content\article\default.php and find:
$full_date = JHtml::_('date', $this->item->publish_up, JText::_('DATE_FORMAT_LC4'));
=>
$full_date = date_format(date_create($this->item->publish_up),'Y-m-d');
Thanks!
