private static Integer parseDayToTransformMonth(String monthStr) {
    Literal<Integer> days = Literal.of(monthStr).to(Types.DateType.get());
    return days.value();
  }
In the partition path days are represented as year-month-day, e.g. 2023-12-12.
This functions converts this string to an integer which represents the days from
'1970-01-01' with the help of Iceberg's type converter.
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/HiveIcebergFilterFactory.java