When filling a date picker field when creating an issue in a Portuguese Atlassian account, the data format is in English

Issue Summary

When the user is filling a date picker field when creating an issue in a Portuguese Atlassian account, the data format is in English, this causes an error informing that the data format is incorrect.

Steps to Reproduce

1. Step 1
   Change your Atlassian account to Portuguese.
2. Step 2
   Access a project from the Projects bar menu.
   Click the Create button to create a new issue and fill a custom date picker field using the built-in data picker calendar.

Expected Results

The month should be in Portuguese format (e.g. Set (Setembro)

Actual Results

The month is in English format (e.g. Sep (September)

Workaround

Change manually the date, or open the project in a new tab, this makes the date picker write the date in the correct format.