MySQL 8.0

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CREATE TABLE your_table (
  date_time DATETIME
);
INSERT INTO your_table (date_time)
VALUES
  ('2023-07-18 10:10:04.000'),
  ('2023-07-18 10:20:04.000'),
  ('2023-07-18 11:10:04.000'),
  ('2023-07-18 11:30:04.000'),
  ('2023-07-18 11:35:04.000'),
  ('2023-07-18 12:10:04.000'),
  ('2023-07-18 12:30:04.000');

Records: 7  Duplicates: 0  Warnings: 0


select * from your_table


date_time


2023-07-18 10:10:04

2023-07-18 10:20:04

2023-07-18 11:10:04

2023-07-18 11:30:04

2023-07-18 11:35:04

2023-07-18 12:10:04

2023-07-18 12:30:04


SELECT group_concat(distinct CONCAT(HOUR(date_time), '-', HOUR(date_time) + 1)) AS hour_range, COUNT(date_time) AS count
FROM your_table
GROUP BY HOUR(date_time)
ORDER BY HOUR(date_time);


hour_range
count


10-11
2

11-12
3

12-13
2