SSIS - converting string to HH:MM:SS
Update:
It was related to specific construction of dataset.
if the time was in range from 00:00:00 to 00:59:00 it was presented as follows (examples):

4 ---&gt; 00:04:00
57 ---&gt; 00:57:00

So the previously posted code did not even take such a case into consideration.
The code solving the problem is following:
LEN(ArrTime) == 1 ? &quot;00:0&quot; + ArrTime + &quot;:00&quot; : (LEN(ArrTime) == 2 ? &quot;00:&quot; + ArrTime + &quot;:00&quot; : (LEN(ArrTime) == 3 ? &quot;0&quot; + SUBSTRING(ArrTime,1,1) + &quot;:&quot; + SUBSTRING(ArrTime,2,2) + &quot;:00&quot; : SUBSTRING(ArrTime,1,2) + &quot;:&quot; + SUBSTRING(ArrTime,3,2) + &quot;:00&quot;))

Now I solved the problem and all works fine.
Maybe someone will need such solution ;)