$globalJobs = [
    ['job' => 1, 'dueDate' => 111],
    ['job' => 2, 'dueDate' => 222]
];

$localJobs = [
    ['job' => 1, 'dueDate' => 333]
];


workMagic($globalJobs,$localJobs);

function workMagic($globalJobs,$localJobs){
    foreach ($globalJobs as $k => $v) {
        updatejob($v, $localJobs);
    };
};

function updateJob($job,$localJobs){
    foreach ($localJobs as $k => $v) {
        if ($job['job'] === $v['job']) { // if exists
	    if ($job['dueDate'] !== $v['dueDate']){ // if dates don't match
	        $v['dueDate'] = $job['dueDate']; // update local record
		var_dump($v);
		var_dump($localJobs);
		return true;
	    };
	} else { // doesn't exist, so add it
	    array_push($localJobs, $job);
	    return true;
	};
    };
    return null;
};