public function buildEventData(array $data)
    {
        $start = strtotime($data['start']['date'] . ' ' . $data['start']['time']);
        $start = date('Y-m-d H:i:s', $start);
        $end = null;

        if (array_key_exists('end', $data)) {
            $end = strtotime($data['end']['date'] . ' ' . $data['end']['time']);
            $end = date('Y-m-d H:i:s', $end);

            if (strtotime($end) < strtotime($start)) {
                throw new DateDifferenceException('Start date bigger then end date!');
            }
        }

        $event = [
            'title' => $data['title'],
            'description' => $data['description'],
            'start' => $start,
            'end' => $end,
            'all_day' => array_key_exists('all_day', $data),
            'border_color' => $data['border_color'],
            'background_color' => $data['background_color'],
            'text_color' => $data['text_color'],
        ];

        return $event;
    }