How to create installment table

installment_table.php

<?php
function nextMonths( $date ){
    $dateArray = [0 => $date];
    for( $i=1; $i<=12; $i++){
        $new_date = date('Y-m-d', strtotime('+'.$i.' months', strtotime($date) ) );
        $next_month = date('Y-m-d', strtotime('last day of next month', strtotime( end($dateArray) ) ));
        if ( date('m', strtotime($new_date) ) != date('m', strtotime($next_month)) ){            
            $dateArray[] = $next_month;
        } else {
            $dateArray[] = $new_date;
        }
    }
    return $dateArray;
}
$date = '2016-12-31';
print_r( nextMonths( $date ) );
?>