Minor Description
Currently, when we perform count with timestamp types, it prints the internal representation as the column name as below:
scala> Seq(new java.sql.Timestamp(1)).toDF("a").groupBy("a").pivot("a").count().show() +--------------------+----+ | a|1000| +--------------------+----+ |1969-12-31 16:00:...| 1| +--------------------+----+
It seems this should be
+--------------------+-----------------------+ | a|1969-12-31 16:00:00.001| +--------------------+-----------------------+ |1969-12-31 16:00:...| 1| +--------------------+-----------------------+
