Help with converting time

Hi
I have this output in a repeating table to calculate time lapsed between 4 different fields
{{(TimeIn.secondsUntil(TimeOutLunch) + TimeInLunch.secondsUntil(TimeOut))}}
is there a way to output this in hours minutes and seconds - HH:mm:ss
I have tried using timeUntil rather than seconds until but it does not work.