Issue Summary

In the Look And Feel settings of a site, it states the following:
 

Use ISO8601 standard in Date Picker
Turning it on will cause Monday to be the first day of week in the Date Picker, as specified by the ISO8601 standard

Our docs slightly contradict this:
https://support.atlassian.com/jira-cloud-administration/docs/configure-the-look-and-feel-of-jira-applications/#Change-date-and-time-formats
 

These settings don't apply to the issue view, which formats dates and times based on your language preferences.

 
I would take the docs to mean that the setting will affect date pickers not on the issue view, but from testing the ISO8601 Look and Feel setting has no impact anywhere. The text in the Look and Feel UI therefore causes confusion.

Steps to Reproduce

1. On <YOUR SITE NAME>.atlassian.net/secure/admin/LookAndFeel!default.jspa enable "Use ISO8601 standard in Date Picker"
   
2. View various date pickers in your site:
   Issue view date-time custom field (Monday start):
   

Issue view date-type system field (Monday start) :

Edit sprint modal (Sunday start):

Issue navigator search (Sunday start):

Boarding settings > Working days (Sunday start):

Expected Results

Enabling ISO8601 standard in Date Picker in Look and Feel settings will result in all date pickers appearing differently, specifically with Monday showing as the first day of the week.

Turning on Confusion caused by Look and Feel setting "Use ISO8601 standard in Date Picker" will cause Monday to be the first day of week in the Date Picker, as specified by the ISO8601 standard

Actual Results

Enabling ISO8601 standard in Date Picker in Look and Feel settings has no effect on any date pickers Jira-wide. Throughout the site some date pickers show Monday as the start Date and others show Sunday.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available