-- create
CREATE TABLE `TIME` (
id integer PRIMARY KEY,
time_start datetime NOT NULL,
time_interval integer NOT NULL
);
-- insert
INSERT INTO `TIME` VALUES (0001, '2025-06-23 10:00:00', 3600);
INSERT INTO `TIME` VALUES (0002, '2025-06-23 10:30:00', 1800);
INSERT INTO `TIME` VALUES (0003, '2025-06-23 11:12:00', 2700);
-- fetch
SELECT `id`, `time_start` AS "start [date]", `time_interval` AS "interval [sec]",
DATE_ADD(`time_start`, INTERVAL `time_interval` SECOND) AS "end [date]",
TIMEDIFF(DATE_ADD(`time_start`, INTERVAL `time_interval` SECOND), NOW()) AS "left"
FROM `TIME`;
Demo:
https://onecompiler.com/mysql/43nkx3aubPS. Przy dużej ilości wpisów zalecam stworzenie widoku zamiast odpalać "raw SQL" za każdym razem