<?php
$month_name = [
  ["months" =>"april"],
  ["months" =>"may"],
  ["months" =>"june"],
  ["months" =>"july"],
  ["months" =>"august"],
  ["months" =>"september"],
  ["months" =>"october"],
  ["months" =>"november"],
  ["months" =>"december"],
  ["months" =>"january"],
  ["months" =>"february"],
  ["months" =>"march"]
];


$months = [
	["months" => "april"],
	["months" => "may"],
	["months" => "october"]
];

$due_months = array_diff_assoc($month_name, $months);
print_r($due_months);