Issue Summary

When language is Korean/Japanese/Chinese, Date Time Picker is still filling 'AM'/'PM' in the field, which users have to manually change to successfully submit the field.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Create an issue with a Date Time Picker field
2. Change the language in user profile to Korean
3. Edit the issue to select a date time and save

Expected Results

• The issue can be directly saved 
• The Date Time Picker should not use 'AM'/'PM'

Actual Results

• Error appears when saving: Invalid date format. Please enter the date in the format "dd/MMM/yy h:mm a"
• Users have to manually change 'PM' to '오후' for the issue to be saved:
  

Language summary

The same behaviour can be observed in Japanase and Chinese. Users have to manually change 'AM'/'PM' to corresponding words in order to use Date Time Picker: 

Workaround

1. Go to Administration > System > Advanced Settings
2. Change the following parameters to use 24-hour time:

   jira.date.time.picker.java.format = dd/MMM/yy HH:mm
   

   jira.date.time.picker.javascript.format = %e/%b/%y %H:%M