SELECT post_id, FROM_DAYS(TO_DAYS(start)+delta)iDate FROM( SELECT post_id, MIN(STR_TO_DATE(meta_value,'%Y-%m-%d'))start, MAX(STR_TO_DATE(meta_value,'%Y-%m-%d'))finish FROM wp_2_posts INNER JOIN wp_2_postmeta ON wp_2_posts.id=wp_2_postmeta.post_id WHERE meta_key IN ('event_from','event_till') AND wp_2_posts.post_type='event' GROUP BY post_ID )main INNER JOIN ( SELECT 0 )numbers ON TO_DAYS(start)+delta <= TO_DAYS(finish) order by iDate desc LIMIT 10

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