How do I calculate the difference between two timestamps in SQLite?

I’m struggling to figure out how to correctly calculate the difference in minutes between two timestamps in one of my tables (TIMEIN and TIMEOUT)

Here’s what the table looks like (only 3 rows):

This is my current SQL, however it doesn’t output what I want.

SELECT (T.DATE + T.TIMEIN - T.DATE + T.TIMEOUT) AS `Duration`

FROM Transport T;

Here’s my output:

It should be outputting:
|Duration|
|:——-|
|60 |
|70 |
|105 |

I tried this without using the date, however that lead to an output of -1 for all rows.

>Solution :

Assuming that TIMEOUT is always greater than TIMEIN you can subtract the unix epochs of the 2 values and divide by 60 to get the number of minutes:

SELECT (strftime('%s', TIMEOUT) - strftime('%s', TIMEIN)) / 60 AS Duration
FROM Transport;

See the demo.