incorrect timezone handling for java.sql.Time

[peterhalicky]

1. What version of JDBC driver are you using?
   3.21.0

2. What operating system and processor architecture are you using?
   MacOS 15.2, Apple Silicon (ARM)

3. What version of Java are you using?
   openjdk 21.0.5 (temurin)

4. What did you do?

Create a table with a TIME column, insert a row with value 12:34:56. My local timezone is UTC+1, snowflake is in UTC.
See: https://github.com/peterhalicky/snowflake-jdbc-time-bug

5. What did you expect to see?

I expect that when I query the row and use ResultSet.getTime on the column, I get the same value. But instead I got 11:34:56. I suspect this is a problem in the JDBC driver, since snowflake as such doesn't really carry timezone in the TIME column. I would expect that PreparedStatement.setTime() and ResultSet.getTime() are consistent when converting to/from java.sql.Time.

6. Can you set logging to DEBUG and collect the logs?

Attached.
snowflake_jdbc0.log

[peterhalicky]

Note that the problem seems to be on insert (i.e. PreparedStatement.setTime()); when I inspect the table contents at app.snowflake.com (the web interface), it's showing 11:34:56.

[sfc-gh-dszmolka]

hi there - thanks for raising this issue.
Can you please check the repro from my colleague in #1805 (comment) ?
I suspect what you're seeing is dependent on current values of JDBC_USE_SESSION_TIMEZONE and TIMEZONE in the session.

[peterhalicky]

Yes, it is very likely dependent on a variety of timezone related settings. I did not touch neither one of the values in my tests, so it is using whatever defaults are in place. In #1805 the time value is sent as a literal in the SQL statement. My tests and observations indicate that the problem is when passing a java.sql.Time value into a PreparedStatement. Regardless of the scenario and timezone configuration, I would expect that the conversions are consistent with each other -- my test shows that they're not.