>I haven't yet looked at what the others have posted, but this is what I use:
>

FUNCTION ShowTime(m.tnElapsed)
>LOCAL m.cTime,m.nHours
>m.nHours = SET("HOURS")
>SET HOURS TO 24
>m.cTime = TTOC(DTOT(DATE(2005,01,01))+m.tnElapsed,2)
>SET HOURS TO (m.nHours)
>RETURN m.cTime
>

Here is what I currently have based on Sergey's message Re: How to calculate elapsed time Thread #1016916 Message #1119600

function SecondsToTime
lparameters tnSeconds
local lcElapsedTime
if m.tnSeconds > 86400 && More than one day
	lcElapsedTime = padl(int(m.tnSeconds/86400),2,'0') + ":" + substr(ttoc({^2006/01/01 00:00:00} + m.tnSeconds,3),12)
else
	lcElapsedTime = substr(ttoc({^2006/01/01 00:00:00} + m.tnSeconds,3),12)
endif
return m.lcElapsedTime
endfunc