Issue Summary

Daylight Saving Time (DST) and similar time changes are not reflected in Time zone options in General settings

Steps to Reproduce

1. During Daylight Saving Time, go to Jira settings > System > General settings, and press the "Edit settings" button
2. In the "Internationalization" section, expand the options for Default User Time zone

Expected Results

The list of options shows different places, and their current time zone, considering DST.

Actual Results

The options displayed (and applied) in the Default User Time Zone don't consider DST

Normally, this is not an issue as the time zone selection is overridden by the User's own Time zone settings, which do update automatically to reflect when DST is in effect or not, but when an Atlassian Account is created (like in a migration) it doesn't have any time zone selected, so it will default to Jira's time zone settings, and this can cause confusion as to why some users see a date/times different to other users:

Workaround

• Change the time zone option according to the actual time zone according to the changes in DST, for example, if London is in GMT+1 during DST, select any time zone that gives GMT+1 from the list, like Amsterdam.
• Ask your users to select a time zone in their Atlassian Account preferences (https://id.atlassian.com/manage-profile/account-preferences), so the default Jira time zone settings are not used.