<?php use PhpOffice\PhpSpreadsheet\Shared\Date; return [ [ 5, [-1, 0, 1, 2, 3], ], [ 7, [ Date::stringToExcel('1900-02-01'), 0, null, 1.2, '', 2.4, '', 3.6, '', 4.8, 'Not a numeric', 6, ], ], ];