Couldn't get the date correctly in Joomla! v.3.9.14, here's my (proven) solution:
$oUser_TZ = JFactory::getUser()->getTimezone();
$aUser_tz = (array)$oUser_TZ; // almost sure this step is not that necessary
$full_date = JFactory::getDate('now', $aUser_tz['timezone']); // pretty sure $oUser_tz->timezone will work
// I had try to use $full_date->...