public function getDeltaTimezone($phpTimezone)
    {
        if (!($phpTimezone instanceof DateTimeZone)) {
            $phpTimezone = new DateTimeZone($phpTimezone);
        }
        $data = $this->getDatabaseTimestamps();
        extract($data);
        $sometimesSame = false;
        $maxDeltaMinutes = 0;
        foreach ($timestamps as $index => $timestamp) {
            $databaseValue = new DateTime($databaseDatetimes[$index], $phpTimezone);
            $phpValue = DateTime::createFromFormat('U', $timestamp, $phpTimezone);
            $deltaMinutes = (int) floor(($phpValue->getTimestamp() - $databaseValue->getTimestamp()) / 60);
            if ($deltaMinutes === 0) {
                $sometimesSame = true;
            } else {
                if (abs($deltaMinutes) > abs($maxDeltaMinutes)) {
                    $maxDeltaMinutes = $deltaMinutes;
                }
            }
        }

        if ($maxDeltaMinutes === 0) {
            return null;
        } else {
            return [
                'dstProblems' => $sometimesSame,
                'maxDeltaMinutes' => $maxDeltaMinutes,
            ];
        }
    }