presto-spi/src/main/java/io/prestosql/spi/type/DateType.java/DateType/getObjectValue
class DateType:    @Override
    public Object getObjectValue(ConnectorSession session, Block block, int position)
    {
        if (block.isNull(position)) {
            return null;
        }

        int days = block.getInt(position, 0);
        return new SqlDate(days);
    }