The dates for all but one k2 item has increased the days by 1 day, ie date in the CSV file is 17/09/2015 when imported into a k2 extra field the date shows 18/09/2015
Please help ..thanks!

return $date->format('Y-m-d', false, false);
return ($tz == 'user') ? date('Y-m-d', $old_date) : $date->format('Y-m-d', false, false);
I really didn't the hassle of upgrading right now.. isit necessary?Not necessary you can apply the change manually as well. Find the file administrator/components/com_csvi/models/com_k2/import/itemimport.php and in that file look for the line that says
$value = $this->convertDate($this->$title, 'date');
and replace it with $value = $this->convertDate($this->$title, 'date', 'user');
that should be enough to make it work. Tell me, which timezone is your site set to?