Steps to Reproduce the Issue:

Change the global time zone in Jira settings.
Review older tickets and notice that their timestamps are adjusted to the new time zone.
Create a new ticket to confirm that new tickets have the correct time according to the new time zone.
Expected Behavior:
Old tickets should retain their original timestamps, unaffected by the new time zone setting. New tickets should use the updated time zone for their timestamps.

Actual Behavior:

Older tickets' timestamps are adjusted according to the new time zone.
New tickets are created with the correct time, based on the new time zone.
Impact:
This behavior can cause confusion in the traceability of events and affect reporting that depends on ticket creation/modification times.