Elgg\Database\EntityTable::getDates PHP Method

    public function getDates($type = '', $subtype = '', $container_guid = 0, $order_by = 'time_created')
    {
        $where = array();
        if ($type != "") {
            $type = sanitise_string($type);
            $where[] = "type='{$type}'";
        }
        if (is_array($subtype)) {
            $tempwhere = "";
            if (sizeof($subtype)) {
                foreach ($subtype as $typekey => $subtypearray) {
                    foreach ($subtypearray as $subtypeval) {
                        $typekey = sanitise_string($typekey);
                        if (!empty($subtypeval)) {
                            if (!($subtypeval = (int) get_subtype_id($typekey, $subtypeval))) {
                                return false;
                            }
                        } else {
                            $subtypeval = 0;
                        }
                        if (!empty($tempwhere)) {
                            $tempwhere .= " or ";
                        }
                        $tempwhere .= "(type = '{$typekey}' and subtype = {$subtypeval})";
                    }
                }
            }
            if (!empty($tempwhere)) {
                $where[] = "({$tempwhere})";
            }
        } else {
            if ($subtype) {
                if (!($subtype_id = get_subtype_id($type, $subtype))) {
                    return false;
                } else {
                    $where[] = "subtype={$subtype_id}";
                }
            }
        }
        if ($container_guid !== 0) {
            if (is_array($container_guid)) {
                foreach ($container_guid as $key => $val) {
                    $container_guid[$key] = (int) $val;
                }
                $where[] = "container_guid in (" . implode(",", $container_guid) . ")";
            } else {
                $container_guid = (int) $container_guid;
                $where[] = "container_guid = {$container_guid}";
            }
        }
        $where[] = _elgg_get_access_where_sql(array('table_alias' => ''));
        $sql = "SELECT DISTINCT EXTRACT(YEAR_MONTH FROM FROM_UNIXTIME(time_created)) AS yearmonth\n\t\t\tFROM {$this->db->prefix}entities where ";
        foreach ($where as $w) {
            $sql .= " {$w} and ";
        }
        $sql .= "1=1 ORDER BY {$order_by}";
        if ($result = $this->db->getData($sql)) {
            $endresult = array();
            foreach ($result as $res) {
                $endresult[] = $res->yearmonth;
            }
            return $endresult;
        }
        return false;
    }