For one of the wikis I am maintaining, we needed to contact the people who contributed less than “X” days ago. I quickly checked the MediaWiki REST-based API, but I didn’t seem easy or feasible, so I did it in SQL:
select u.user_email as email, max(r.rev_timestamp) as last_change from revision r, user u where r.rev_user = u.user_id and r.rev_timestamp group by u.user_email;
Import the result in Excel, transform the MediaWiki timestamp to an Excel date, using the following formula:
From that point on, it’s trivial to compute the age in days, sort and export.