Need to sum up HHMMS AM/PM DD/MM/YYYY and a HH:MM:SS.

[tester_V]

Greetings!
I have a time string, it shows the time something started running:
08:31:27 PM 01/02/2023
And the total 'HH:MM:SS' it took to finish the run:
01:22:14
I need to create the ‘finished running’ string by adding the HH:MM:SS to the 08:31:27 PM 01/02/2023.

Should I split the ‘start string’, get the hh:mm:ss, and convert that to total seconds?
Then convert to seconds the “finish run” to seconds.
Sum up both seconds, convert the total seconds to HH:MM:SS, and add the Date time to that.
All of it would look like this:
08:31:27 PM 01/02/2023, 09:53:41 27 PM 01/02/2023

It will work but I do not like how it looks, kind of ugly…
Any thoughts on this?
Thank you.