USE frwiki_p;

SELECT date, COUNT(time) + 1 AS edit_count, AVG(time) AS average_interval

FROM

  (SELECT DATE(DATE_SUB(rev_timestamp, INTERVAL 10 HOUR)) AS date,

          TIMESTAMPDIFF(MINUTE, @previous, rev_timestamp) AS time,

          @previous := rev_timestamp

   FROM (SELECT @previous := 0) AS _

   JOIN revision

   JOIN page ON page_id = rev_page

   WHERE page_namespace = 0

   AND page_title = 'Insomnie'

   AND (HOUR(rev_timestamp) > 19 OR HOUR(rev_timestamp) < 5)

   ORDER BY rev_timestamp) AS deltas

WHERE time < 600

GROUP BY date;