Sprint date shows an incorrect format for the start date and end date

Issue Summary

The Sprint Start date and End date will show incorrectly when modifying the date time picker format in the Advanced Settings. Instead of 01-Jan-2020 you will see 01-Jan-0020 (the year format is incorrect).

Steps to Reproduce

1. Go to the General configuration then Advanced Settings
2. Set the jira.date.picker.java.format to dd/MMM/yyyy and update
3. Set the jira.date.time.picker.java.format to dd/MMM/yyyy h:mm a and update
4. Go to your Classic Software Scrum board and edit the Start date or End date by opening the calendar icon
   

Expected Results

14/Oct/2019 11:17 AM

Actual Results

14/Oct/0019 11:17 AM

Workaround

You can edit the year manually by clicking on it, or simply change the date format from the Advanced settings (set it to yy).