time elapsed between multiple dates, MySQL

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drop table calendar;

create table calendar as 
SELECT '2017-12-31 09:00:00' - INTERVAL c.number DAY AS start_datetime,'2017-12-31 22:00:00' - INTERVAL c.number DAY AS end_datetime
FROM (SELECT singles + tens + hundreds number FROM 
( SELECT 0 singles
UNION ALL SELECT   1 UNION ALL SELECT   2 UNION ALL SELECT   3
UNION ALL SELECT   4 UNION ALL SELECT   5 UNION ALL SELECT   6
UNION ALL SELECT   7 UNION ALL SELECT   8 UNION ALL SELECT   9
) singles JOIN 
(SELECT 0 tens
UNION ALL SELECT  10 UNION ALL SELECT  20 UNION ALL SELECT  30
UNION ALL SELECT  40 UNION ALL SELECT  50 UNION ALL SELECT  60
UNION ALL SELECT  70 UNION ALL SELECT  80 UNION ALL SELECT  90
) tens  JOIN 
(SELECT 0 hundreds
UNION ALL SELECT  100 UNION ALL SELECT  200 UNION ALL SELECT  300
UNION ALL SELECT  400 UNION ALL SELECT  500 UNION ALL SELECT  600
UNION ALL SELECT  700 UNION ALL SELECT  800 UNION ALL SELECT  900
) hundreds
ORDER BY number DESC) c  
WHERE c.number BETWEEN 0 and 364
;

drop table date_ranges;

CREATE TABLE date_ranges (
`Start` TIMESTAMP,
`End` TIMESTAMP
);

INSERT INTO date_ranges VALUES
('2017-01-01 07:15:00','2017-01-02 11:30:00'),
('2017-01-21 09:15:00','2017-02-02 21:30:00'),
('2017-07-29 00:15:00','2017-08-31 20:10:00')
;

select d.`start`,d.`end`,sum(timestampdiff(minute,greatest(d.`start`,c.start_datetime) , least(d.`end`,c.end_datetime))) as total_time
from calendar c
left join date_ranges d on date(c.start_datetime) >= date(d.`start`) and date(c.start_datetime) <= date(d.`end`)
where d.`start` is not null and d.`end` is not null
group by d.`start`,d.`end`
;


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