Enable calendar in date pickers

In some cases you can get an error “The JIRA Calendar does not currently support your language.“ when you trying to change date with built-in datepicker

To solve this problem you should:

1. Add Javascript file with Ukrainian translation to atlassian-jira/includes/js/calendar/lang/

2. Add this javascript file as a downloadable web resource. Modify the file system-webresources-plugin.xml to include the following:
   

   <web-resource key="calendar-uk" i18n-name-key="admin.web.resources.plugin.calendar.uk.name" name="Calendar"
   state='enabled'>
     <resource type="download" name="calendar-uk.js" location="/includes/js/calendar/lang/calendar-uk.js">
       <param name="source" value="webContextStatic"/>
     </resource>
     <context>atl.global</context>
     <context>atl.general</context>
     <context>customerportal</context>
   </web-resource>

3. Add an entry mapping the filename to your language code uk=calendar_uk.js in the file "jira-install-dir"/atlassian-jira/WEB-INF/classes/calendar-language-util.properties

4. Reboot Jira.