Reading xls date in php

Excel stores dates and times as a number representing the number of days since 1900-Jan-0, plus a fractional portion of a 24 hour day: ddddd.tttttt . This is called a serial date, or serial date-time.

$date = date_create('30-12-1899');
date_add($date, date_interval_create_from_date_string('42403 days'));
echo date_format($date, 'Y-m-d');