Online PHP editor | output for BcMe8

<?php //$datetimeStart1 = new DateTime('2017-05-16'); //$datetimeEnd1 = new DateTime('2017-07-19'); //$datetimeStart2 = new DateTime('2017-07-12'); //$datetimeEnd2 = new DateTime('2017-07-22'); $datetimeStart1 = DateTime::createFromFormat('Y-m-d','2017-05-16'); $datetimeEnd1 = DateTime::createFromFormat('Y-m-d','2017-07-19'); $datetimeStart2 = DateTime::createFromFormat('Y-m-d','2017-07-12'); $datetimeEnd2 = DateTime::createFromFormat('Y-m-d','2017-07-22'); // following http://stackoverflow.com/questions/325933/determine-whether-two-date-ranges-overlap if ($datetimeStart1 < $datetimeEnd2 && $datetimeEnd1 > $datetimeStart2) { echo min($datetimeEnd1,$datetimeEnd2)->diff(max($datetimeStart2,$datetimeStart1))->days+1; } else { echo 'no overlap'; }