class EthiopianCalendar extends ChronologyBasedCalendar {

    @Override
    public int daysInMonth( int year, int month )
    {
        if ( month > 12 )
        {
            throw new RuntimeException( "Illegal month, must be between 1 and 12, was given " + month );
        }

        return 30;
    }

    protected  EthiopianCalendar();

}