presto-rcfile/src/main/java/io/prestosql/rcfile/text/DateEncoding.java/DateEncoding/encodeValue
class DateEncoding:    private void encodeValue(Block block, int position, SliceOutput output)
    {
        long days = type.getLong(block, position);
        long millis = TimeUnit.DAYS.toMillis(days);
        buffer.setLength(0);
        HIVE_DATE_PARSER.printTo(buffer, millis);
        for (int index = 0; index < buffer.length(); index++) {
            output.writeByte(buffer.charAt(index));
        }
    }