$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 => $v) {
        if (!updatejob($v, $localJobs)){ // couldn't find it
            array_push($localJobs, $v); // add to local
        };
    };
    var_dump($localJobs[0]);
};

function updateJob($job,$localJobs){
    foreach ($localJobs as $k => &$v) {
        if ($v['job'] === $job['job']) { // if job already exists in local
            if ($v['dueDate'] !== $job['dueDate']){ // and dates don't match
                $v['dueDate'] = $job['dueDate']; // then update local
                var_dump($localJobs[0]);
                return true;
            };
        };
    };
    return null; // couldn't find it
};