From https://debezium.zulipchat.com/#narrow/channel/348250-community-oracle/topic/CDC.20and.20Snapshots.20have.20different.20timezones.3F/near/502364318

During a snapshot event:

• payload.source.ts_ms = 1740653607000 which is 2025-02-27T10:53:27, which is +0100
• payload.ts_ms = 1740650023451 which is 2025-02-27T09:53:43, which is correct

In Oracle:
SELECT DBTIMEZONE FROM DUAL reports +00:00.
SELECT SESSIONTIMEZONE FROM DUAL reports +00:00.
SELECT SYSTIMESTAMP FROM DUAL reports 2025-02-27T21:08:09.438218+01:00
SELECT CURRENT_TIMESTAMP FROM DUAL reports 2025-02-27T20:08:33.422589Z

When we fetch the timestamp for the snapshot SCN, it appears that timestamp is not adjusted by the database timezone.