I made a spreadsheet calculating how long a user is on line(VPN)
From until = total time
Because this can go overnight, I make the sum with an IF-statement.
if(from <= until;until-from;24-from+until)
This works completely correct.
Then I make a sum of all these times, and here it goes wrong.
If there is a sum calculated with the false-statement, then the sum of the
total hours goes completely wrong. As long as every time is calculated with
the true-statement, the total result is correct.

This even goes wrong by making a sum of one cell.
example
from until total
22:58 8:42 9:44

total 561:44

this is the result I get when making a sum of the column total, format as
[u]:mm

Does anyone have a solution for this?