Helpful functions to figure out future dates to days, months, years. Stolen from PHP.net comments for mktime.

PHP Date helpers

<?php
    public function addMonthToDate($timeStamp, $totalMonths=1){
        // You can add as many months as you want. mktime will accumulate to the next year.
        $thePHPDate = getdate($timeStamp); // Covert to Array    
        $thePHPDate['mon'] = $thePHPDate['mon']+$totalMonths; // Add to Month    
        $timeStamp = mktime($thePHPDate['hours'], $thePHPDate['minutes'], $thePHPDate['seconds'], $thePHPDate['mon'], $thePHPDate['mday'], $thePHPDate['year']); // Convert back to timestamp
        return $timeStamp;
    }
    
    public function addDayToDate($timeStamp, $totalDays=1){
        // You can add as many days as you want. mktime will accumulate to the next month / year.
        $thePHPDate = getdate($timeStamp);
        $thePHPDate['mday'] = $thePHPDate['mday']+$totalDays;
        $timeStamp = mktime($thePHPDate['hours'], $thePHPDate['minutes'], $thePHPDate['seconds'], $thePHPDate['mon'], $thePHPDate['mday'], $thePHPDate['year']);
        return $timeStamp;
    }

    public function addYearToDate($timeStamp, $totalYears=1){
        $thePHPDate = getdate($timeStamp);
        $thePHPDate['year'] = $thePHPDate['year']+$totalYears;
        $timeStamp = mktime($thePHPDate['hours'], $thePHPDate['minutes'], $thePHPDate['seconds'], $thePHPDate['mon'], $thePHPDate['mday'], $thePHPDate['year']);
        return $timeStamp;
    }
?>