MySQL 5.6

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CREATE TABLE `time` (
  `id` int(11) NOT NULL,
  `user_id` int(11) NOT NULL,
  `date` date NOT NULL,
  `start_time` time NOT NULL,
  `end_time` time NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `time` (`id`, `user_id`, `date`, `start_time`, `end_time`) VALUES
(1, 1, '2019-07-07', '08:00:00', '12:00:00'),
(2, 1, '2019-07-07', '16:00:00', '22:00:00'),
(3, 1, '2019-07-06', '10:00:00', '18:00:00');
CREATE TABLE `schedule` (
  `id` int(11) NOT NULL,
  `user_id` int(11) NOT NULL,
  `date` date NOT NULL,
  `start_time` time NOT NULL,
  `end_time` time NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

--
-- Dumping data for table `schedule`
--

INSERT INTO `schedule` (`id`, `user_id`, `date`, `start_time`, `end_time`) VALUES
(1, 1, '2019-07-07', '08:00:00', '12:00:00'),
(2, 1, '2019-07-07', '16:00:00', '22:00:00'),
(3, 1, '2019-07-06', '10:00:00', '18:00:00');
select
  s.date, s.user_id,
  s.schedule_start, 
  s.schedule_end, 
  t.actual_start, 
  t.actual_end   
from (
  select s.date, s.user_id, 
    min(s.start_time) as schedule_start, 
    min(s.end_time) as schedule_end
  from schedule s
  group by s.date, s.user_id
) s left join (
  select t.date, t.user_id,
    min(t.start_time) as actual_start, 
    min(t.end_time) as actual_end
  from time t
  group by t.date, t.user_id
) t on t.user_id=s.user_id and t.date=s.date 
union
select
  s.date, s.user_id,
  s.schedule_start, 
  s.schedule_end, 
  t.actual_start, 
  t.actual_end   
from (
  select s.date, s.user_id, 
    max(s.start_time) as schedule_start, 
    max(s.end_time) as schedule_end
  from schedule s
  group by s.date, s.user_id
) s left join (
  select t.date, t.user_id,
    max(t.start_time) as actual_start, 
    max(t.end_time) as actual_end
  from time t 
  group by t.date, t.user_id
) t on t.user_id=s.user_id and t.date=s.date 
 


date
user_id
schedule_start
schedule_end
actual_start
actual_end


2019-07-06
1
10:00:00
18:00:00
10:00:00
18:00:00

2019-07-07
1
08:00:00
12:00:00
08:00:00
12:00:00

2019-07-07
1
16:00:00
22:00:00
16:00:00
22:00:00

date	user_id	schedule_start	schedule_end	actual_start	actual_end
2019-07-06	1	10:00:00	18:00:00	10:00:00	18:00:00
2019-07-07	1	08:00:00	12:00:00	08:00:00	12:00:00
2019-07-07	1	16:00:00	22:00:00	16:00:00	22:00:00