Mysql: difference between two timestamps in seconds?

Unit Variety in TIMESTAMPDIFF

TIMESTAMPDIFF isn't just a one-trick pony. It can calculate the time difference in YEARS, MONTHS, DAYS, HOURS, and MINUTES too. That's some serious datetime versatility!

SELECT TIMESTAMPDIFF(MINUTE, 'start_timestamp', 'end_timestamp') AS minutes_difference;
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Shortcomings of UNIX_TIMESTAMP

UNIX_TIMESTAMP() can convert datetime to seconds elapsed since 1970-01-01 00:00:00 UTC. But it doesn't handle dates prior to 1970 or far into the future well:

SELECT UNIX_TIMESTAMP('2055-01-01 12:00:00');
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Returns negative number, returns to the future, Marty McFly style!

In scenarios where you aren't confident about the order of timestamps, ABS can save the day:

SELECT ABS(UNIX_TIMESTAMP('end_timestamp') - UNIX_TIMESTAMP('start_timestamp')) AS seconds_difference;
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Special Cases and TIMESTAMPDIFF's Robustness

Historic Dates

TIMESTAMPDIFF isn’t scared of the past. Date preceding the UNIX epoch? Not a problem. TIMESTAMPDIFF handles your historical data like a champ.

The Future is Now

For timestamps exceeding 2038, TIMESTAMPDIFF holds steady. Where some 32-bit systems shake, TIMESTAMPDIFF stands strong.

Zero-Hour Handling

TIMESTAMPDIFF behaves consistently with time zones and calculates zero-hour differences correctly, whereas raw epoch-based calculations may falter.

Visualization

To visualize the difference in seconds between two timestamps, consider the following:

| Timestamp Event        | Time Moment                    |
| ---------------------- | ------------------------------ |
| Start (⏰)              | 2023-03-01 08:00:00            |
| End (🏁)                | 2023-03-01 08:02:30            |

🕒 Calculating Difference:

SELECT TIMESTAMPDIFF(SECOND, '2023-03-01 08:00:00', '2023-03-01 08:02:30') AS Elapsed_Time;
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Result:

| Elapsed Time           |
| ---------------------- |
| 150 seconds ⏱️         |

No sweat for TIMESTAMPDIFF, ready for the next data sprint!

Advanced TIMESTAMPDIFF Usage

Apply TIME_TO_SEC()

TIME_TO_SEC() won’t operate on a datetime value, but park it in front of a time value, and it’s off to the races:

SELECT TIME_TO_SEC('12:30:00');
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Faster than the lunch crowd to the taco truck!

TIMESTAMPDIFF for data analysis

TIMESTAMPDIFF can pave the way for deeper analysis. Use it to calculate velocities, productivity metrics, or temporal trends:

SELECT COUNT(*), TIMESTAMPDIFF(HOUR, MIN(time), MAX(time)) AS hours_taken FROM tasks;
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TIMESTAMPDIFF vs. UNIX_TIMESTAMP

Remember, although the accepted practice on several posts is to use UNIX_TIMESTAMP() and ABS() to calculate time difference in seconds, it’s good to remember that for portability and accuracy, especially over different dates, TIMESTAMPDIFF outperforms.