Client-side rendered timestamps do not respect timezone in user preference

tl;dr The screenshot says it all. The 10th July 2013 is a Wednesday.

It seems there has been some hacking done to use the Browser's time zone to display dates on the JIRA UI. This is a BUG. The doumentation clearly states:

you can personalise your JIRA account to use a time zone of your choice. This will affect all time-date fields throughout JIRA.

If this is a required feature, that is using the Browser timezone then a number of things need to be addressed:

• Must be consistent across all the UI.
• There must be a preference in the Edit User Profile dialog to allow the options: Use System Default, Use Browser Timezone or I'll set my Timezone
• This must be applied to all the backgound things as well, eg. JQL searches, Subscriptions, Version Overdue calculations etc.
• The documentation must be updated.
• The default behaviour for new users must be configurable.
• The default behaviour for anonymous users must be configurable.
• On upgrade the current behaviour should not change for existing customers.
• What the default is for new BTF and new OD customers must be considered and documented.