Major Description
The conversions of Catalyst's DATE/TIMESTAMPS to/from Java's types java.sql.Date/java.sql.Timestamps have almost the same implementation except addition rebasing op. If we look at switch and diffs arrays of all available time zones, we can detect that there is a time point when all diffs are 0. This is 1900-01-01 00:00:00Z. So, we can compare input micros with the time point and skip conversion for modern timestamps.
