JIRA Agile/Software does not respect JIRA's ISO8601 setting

Summary

JIRA Software/JIRA Agile does not use the ISO8601 formatting for its date pickers.

Environment

JIRA with JIRA Agile/Software.

Steps to Reproduce

1. Setup a JIRA instance with Agile/Software installed;
2. Navigate to Administration > System > Look and Feel and set JIRA to use ISO8601 formatting for date pickers;
3. Navigate to an existing or create a new Agile Scrum board;
4. Create a version using the sidebar under Backlog view or edit an existing sprint.
5. Observe that the date pickers will not respect the ISO8601 setting from JIRA;

Expected Results

JIRA Software should consistently use the ISO8601 setting if it has been configured in JIRA.

Actual Results

JIRA Agile does not apply this setting, as a result the date pickers behave in an inconsistent manner.
This is not affecting the date pickers in the Releases page (version 8.12.3)

Notes

The original report included the following information:

This can be seen in two different places:
Administration -> Greenhopper Configuration -> Non Working Days.
Configure Board -> Non Working Days -> Add Date Button

Workaround

The following workaround has been shown to work for customers on 8.13.x versions, but may not work on all versions of JIRA.

1. Choose Administration (   ) > System. 
2. Select User Interface > Announcement banner in the System panel below.
3. Add the following code snippet into the Announcement field:

   <script>
   (function() {
       if (Calendar) {
           Calendar._setup = Calendar.setup;       
           Calendar.setup = function(arguments) {
               arguments = arguments || {};
               arguments.useISO8601WeekNumbers =true;
               Calendar._setup(arguments); 
           };
       }
   })();
   </script> 
   

4. Select the required Visibility Level for the banner.
5. Click the Set Banner button.