MariaDB 10.3

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CREATE TABLE `leave` (
  ID_LEAVE INT,
  ID_WORKER INT,
  BEGIN_DATE DATETIME,
  END_DATE DATETIME
);
INSERT INTO `leave` VALUES
(3, 26, '2019-03-20 07:00:00', '2019-03-21 15:00:00'),
(4, 22, '2019-03-20 07:00:00', '2019-03-20 15:00:00'),
(5, 4, '2019-04-09 07:00:00', '2019-04-10 15:00:00'),
(6, 9, '2019-04-13 07:00:00', '2019-04-13 15:00:00');
SELECT
  `ID_LEAVE`,
  SEC_TO_TIME(SUM(
    (TIME_TO_SEC(`DailyTimeSeconds`) * 5 * `Weeks`) +            -- time for full weeks
    (TIME_TO_SEC(`DailyTimeSeconds`) * `DaysOutsideFullWeeks`) + -- time for days after full weeks
    (TIME_TO_SEC(`DailyTimeSeconds`) * `CountDaysInFirstWeek`)   -- time for days in first week
  )) AS 'Result'
FROM (
  SELECT
    `ID_LEAVE`, `BEGIN`, `END`,
    LEAST(GREATEST((`CountAllDays` - `CountDaysInFirstWeek` - 2) % 7, 0), 5) AS 'DaysOutsideFullWeeks',  -- count of days outside of full weeks
    CAST(GREATEST(FLOOR((`CountAllDays` - `CountDaysInFirstWeek` - 2) / 7), 0) AS UNSIGNED) AS 'Weeks',  -- count of weeks
    `DailyTimeSeconds`, `CountDaysInFirstWeek`
  FROM (
    SELECT
      ID_LEAVE, DATE(BEGIN_DATE) AS 'BEGIN', DATE(END_DATE) AS 'END',
      GREATEST(5 - WEEKDAY(DATE(BEGIN_DATE)), 0) AS 'CountDaysInFirstWeek',  -- count of days in first week (without weekend)
      DATEDIFF(DATE(END_DATE), DATE(BEGIN_DATE)) + 1 AS 'CountAllDays',      -- count of all days between start and end
      TIMEDIFF(TIME(END_DATE), TIME(BEGIN_DATE)) AS 'DailyTimeSeconds'       -- the time for one day (end time - start time).
    FROM `leave`
  ) t
) t2 GROUP BY ID_LEAVE;


ID_LEAVE
Result


3
24:00:00

4
24:00:00

5
32:00:00

6
00:00:00


SELECT
  `ID_LEAVE`, `BEGIN`, `END`,
  SEC_TO_TIME(
    (TIME_TO_SEC(`DailyTimeSeconds`) * 5 * `Weeks`) +            -- time for full weeks
    (TIME_TO_SEC(`DailyTimeSeconds`) * `DaysOutsideFullWeeks`) + -- time for days after full weeks
    (TIME_TO_SEC(`DailyTimeSeconds`) * `CountDaysInFirstWeek`)   -- time for days in first week
  ) AS 'Result'
FROM (
  SELECT
    `ID_LEAVE`, `BEGIN`, `END`,
    LEAST(GREATEST((`CountAllDays` - `CountDaysInFirstWeek` - 2) % 7, 0), 5) AS 'DaysOutsideFullWeeks',  -- count of days outside of full weeks
    CAST(GREATEST(FLOOR((`CountAllDays` - `CountDaysInFirstWeek` - 2) / 7), 0) AS UNSIGNED) AS 'Weeks',  -- count of weeks
    `DailyTimeSeconds`, `CountDaysInFirstWeek`
  FROM (
    SELECT
      ID_LEAVE, DATE(BEGIN_DATE) AS 'BEGIN', DATE(END_DATE) AS 'END',
      GREATEST(5 - WEEKDAY(DATE(BEGIN_DATE)), 0) AS 'CountDaysInFirstWeek',  -- count of days in first week (without weekend)
      DATEDIFF(DATE(END_DATE), DATE(BEGIN_DATE)) + 1 AS 'CountAllDays',      -- count of all days between start and end
      TIMEDIFF(TIME(END_DATE), TIME(BEGIN_DATE)) AS 'DailyTimeSeconds'       -- the time for one day (end time - start time).
    FROM `leave`
  ) t
) t2;


ID_LEAVE
BEGIN
END
Result


3
2019-03-20
2019-03-21
24:00:00

4
2019-03-20
2019-03-20
24:00:00

5
2019-04-09
2019-04-10
32:00:00

6
2019-04-13
2019-04-13
00:00:00
ID_LEAVE	BEGIN	END	Result
3	2019-03-20	2019-03-21	24:00:00
4	2019-03-20	2019-03-20	24:00:00
5	2019-04-09	2019-04-10	32:00:00
6	2019-04-13	2019-04-13	00:00:00