Github user omalley commented on the issue:
https://github.com/apache/orc/pull/253
*Sigh* This is caused by the fact that Java defined Timestamp badly and
then Hive copied those semantics into the ColumnVector.
We really need to fix these semantics in ORCv2.
I'll also comment that it would probably be nicer to our users if we
weren't modifying the data in the columnVector they passed into us, but clearly
we are already doing that.---
