Online PHP editor | output for MPNPC

<?php function reduceOverlap(array $arr){ $flag = true; while($flag){ $flag = false; foreach($arr as $key1 => $row1){ foreach($arr as $key2 => $row2){ if($key1 === $key2) continue; if(($row1['open'] >= $row2['open'] && $row1['open'] <= $row2['close']) OR ($row1['close'] >= $row2['open'] && $row1['close'] <= $row2['close'])){ $arr[$key1]['open'] = min($row1['open'],$row2['open']); $arr[$key1]['close'] = max($row1['close'],$row2['close']); unset($arr[$key2]); $flag = true; break 2; } } } } return $arr; } function diffTotal(array $arr){ $date = date_create('1970-01-01 00:00'); foreach($arr as $row){ $diff = date_create($row['open'])->diff(date_create($row['close'])); $date->add($diff); } return date_create('1970-01-01 00:00')->diff($date); } $times = [ ['open' => '2023-01-02 09:00:00', 'close' => '2023-01-02 14:00:00'], ['open' => '2023-01-02 11:00:00', 'close' => '2023-01-02 15:00:00'], ['open' => '2023-01-14 10:00:00', 'close' => '2023-01-14 11:00:00'], ]; $arr = reduceOverlap($times); $diffTotal = diffTotal($arr); var_dump($diffTotal);