<?php $statics = ['1481069313' => ['added' => 2, 'removed' => 8],'1481072913' => ['added' => 7, 'removed' => 12], '1481674113' => ['added' => 18, 'removed' => 5]]; function getStatics($staticsCat, $firstTimestamp, $lastTimestamp) { global $statics; foreach($statics as $timestamp => $cat){ if ($timestamp >= $firstTimestamp && $timestamp <= $lastTimestamp) { $count += $cat["$staticsCat"]; } } echo $count; } getStatics('added', strtotime('2016-12-06 00:00:00'), strtotime('2016-12-08 00:00:00'));