I'm using data from Excel2007
as parsed by PHPExcel, and dates come out as days since 1900.
How can I convert to string of YYYY-MM-DD
(or anything similar)?
Or use
$phpDate = PHPExcel_Shared_Date::ExcelToPHP($cell->getCalculatedValue());
to convert an Excel/PHPExcel date to a PHP date/timestamp, and then use standard PHP date() function for formatting