Get a list of (date) quarters between two given dates. Return array of objects with information about each quarter

DateQuartersUtil.php

/**
 * Class DateQuartersUtil
 * @package UtilsBundle\Classes
 */
class DateQuartersUtil
{
    /**
     * Return quarters between tow dates. Array of objects
     * @param $start_date
     * @param $end_date
     * @return array
     */
    public static function getQuarters($start_date, $end_date){

        $quarters = array();

        $startMonth = date( 'm', strtotime($start_date) );
        $startYear = date( 'Y', strtotime($start_date) );

        $endMonth = date( 'm', strtotime($end_date) );
        $endYear = date( 'Y', strtotime($end_date) );

        $startQuarter = ceil($startMonth/3);
        $endQuarter = ceil($endMonth/3);

        $quarter = $startQuarter; // variable to track current quarter

        // Loop over years and quarters to create array
        for( $y = $startYear; $y <= $endYear; $y++ ){
            if($y == $endYear)
                $maxQtr = $endQuarter;
            else
                $maxQtr = 4;

            for($q=$quarter; $q<=$maxQtr; $q++){

                $currentQuarter = new \stdClass();

                $endMonthNum = self::zeroPad($q * 3);
                $startMonthNum = ($endMonthNum - 2);

                $qStartMonth = self::monthName($startMonthNum);
                $qEndMonth = self::monthName($endMonthNum);

                $currentQuarter->title = "Q$q ('$y)";
                $currentQuarter->description = "Qtr $q ($qStartMonth - $qEndMonth) $y";
                $currentQuarter->start = "$y-$startMonthNum-01";      // yyyy-mm-dd
                $currentQuarter->end = "$y-$endMonthNum-" . self::monthEndDate($y, $endMonthNum);

                $quarters[] = $currentQuarter;
                unset($currentQuarter);
            }

            $quarter = 1; // reset to 1 for next year
        }

        return $quarters;
    }

    /**
     * get month name from number
     * @param $monthNumber
     * @return false|string
     */
    protected static function monthName($monthNumber){
        return date('F', mktime(0, 0, 0, $monthNumber, 10));
    }

    /**
     * get get last date of given month (of year)
     * @param $year
     * @param $monthNumber
     * @return false|string
     */
    protected static function monthEndDate($year, $monthNumber){
        return date("t", strtotime("$year-$monthNumber-1"));
    }

    /**
     * return two digit month or day, e.g. 04 - April
     * @param $number
     * @return string
     */
    protected static function zeroPad($number){
        if($number < 10) {
            return "0$number";
        }
        return "$number";
    }

}