gistfile1.sql

      SELECT id, user_id,
              CASE
                WHEN HOUR(starts_on) = 22 THEN TIMESTAMPADD(HOUR, 2, starts_on)
                WHEN HOUR(starts_on) = 23 THEN TIMESTAMPADD(HOUR, 1, starts_on)
              END AS starts_on,
              CASE
                WHEN HOUR(ends_on) = 21 THEN TIMESTAMPADD(HOUR, 2, ends_on)
                WHEN HOUR(ends_on) = 22 THEN TIMESTAMPADD(HOUR, 1, ends_on)
              END AS ends_on
       FROM activity_years
       WHERE
         user_id = #{user.id}
       HAVING 
         (YEAR(starts_on) = #{start_date.year}
          OR
          YEAR(ends_on) = #{end_date.year})