>>> spark.conf.set("spark.sql.session.timeZone", "UTC")
>>> sql = """
... SELECT
... TIMESTAMP '1997-01-31 09:26:56.66666666UTC+08:00' AS a,
... TIMESTAMP '2015-06-30 12:00:00.999999UTC-05:00' AS b
... """
>>> spark.sql(sql).show(truncate=False)
+--------------------------+--------------------------+
|a                         |b                         |
+--------------------------+--------------------------+
|1997-01-31 01:26:56.666666|2015-06-30 17:00:00.999999|
+--------------------------+--------------------------+