WITH profiles AS (
       SELECT u.user_id as user_id,
              DATE_TRUNC('month', MIN(e.event_time))::date AS start_date
       FROM tools_shop.events as e
       JOIN tools_shop.users as u ON e.user_id = u.user_id
       JOIN tools_shop.orders as o ON o.user_id = u.user_id
       GROUP BY u.user_id)
SELECT DISTINCT 
p.start_date,
p.user_id
FROM profiles as p
JOIN tools_shop.events as e ON e.user_id = p.user_id