PayableDateController.php

public function _getHolidayList() {
        $newArray = array();
        $dt = new \DateTime();

        $newArray[] = $dt->modify("First day of January")->format('Y-m-d');
        $newArray[] = $dt->modify("Third Monday of January")->format('Y-m-d');
        $newArray[] = $dt->modify("Third Monday of February")->format('Y-m-d');
        $newArray[] = $dt->modify("Last Monday of May")->format("Y-m-d");
        $newArray[] = $dt->modify("July 4")->format("Y-m-d");
        $newArray[] = $dt->modify("First Monday of September")->format("Y-m-d");
        $newArray[] = $dt->modify("Second Monday of October")->format("Y-m-d");
        $newArray[] = $dt->modify("November 11")->format("Y-m-d");
        $newArray[] = $dt->modify("Fourth Thursday of November")->format("Y-m-d");
        $newArray[] = $dt->modify("December 25")->format("Y-m-d");

        return $newArray;
    }