Strange behavior of timezone

I found that the timezone behavior for DATETIME is a little strange, could you help to confirm it?
My timezone is +8, this is my test environment.

• MySQL: 8.0.30
• Node: 20.6.1
• Mysql2: 3.6.2

Command to get connectio pool:

pool = require('mysql2/promise').createPool({
    host: xxx,
    user: xxx,
    password: xxx,
    database: xxx,
    timezone: "******"
});

This is my test data.

mysql> select rec_dt from TB1;
+---------------------+
| rec_dt              |
+---------------------+
| 2023-10-13 09:15:57 |
+---------------------+

This is my test result.

• timezone is not set, it returns 2023-10-13T01:15:57.000Z
• timezone is "local", it returns 2023-10-13T01:15:57.000Z => it should be 09:15:57, and not add 'Z'
• timezone is "Z", it returns 2023-10-13T09:15:57.000Z => it should be 01:15:57
• timezone is "xxxxx", it returns 2023-10-13T09:15:57.000Z

of course, I got an error message when I set it to xxx, Ignoring invalid timezone passed to Connection: xxxxx. This is currently a warning, but in future versions of MySQL2, an error will be thrown if you pass an invalid configuration option to a Connection

Start at the createPool timezone option and the DATETIME result parsing path, using the supplied MySQL, Node, and mysql2 versions to reproduce each timezone setting. Compare the returned values with the reported database value and determine the intended behavior for invalid timezone strings; done means the behavior is confirmed and the issue has a specific expected outcome.