I will help myself now. Advance thank you to myself.
SELECT u.firstname AS 'Firstname' , u.lastname AS 'Lastname', cat.name AS 'Organisation', c.fullname AS 'course',
DATE_FORMAT(FROM_UNIXTIME(p.timecompleted),'%Y-%m-%d') AS completed,
DATE_FORMAT(DATE_ADD(FROM_UNIXTIME(p.timecompleted),INTERVAL 1 YEAR), '%Y-%m-%d') AS expiration_date
FROM prefix_course_completions AS p
JOIN prefix_course_categories AS cat
JOIN prefix_course AS c ON p.course = c.id
JOIN prefix_user AS u ON p.userid = u.id
WHERE c.enablecompletion = 1
ORDER BY u.firstname
