infocubic
ok let's do it one step at once
1) Add new extra fields
Go to this file /templates/ja_events_ii/etc/extrafields/events.xml and add new extrafield let's say new date so it will be
<field name="link_5" type="text" label="TPL_DATE_EVENT_2" description="TPL_DATE_2_EVENT_DESC" size="40" filter="RAW"/>
2) edit this file /templates/ja_events_ii/html/com_content/category/event_item.php and add your new link
http://prntscr.com/j58u26
3) edit this file /templates/ja_events_ii//html/com_content/article/default.php
http://prntscr.com/j58uwi
4) remember to add translations for new strings added
http://prntscr.com/j58w5k