Gregory,

If SET HOURS is set to 24 ttoc() can do all of the work for you for durations less than 24 hours:

? ttoc( {^2002-01-01 00:00 } + timetaken, 2 )


>x = ttoc( { 00:00 } + timetaken, 1)
>x = substr(x,9,2) + ':' + substr(x,11,2) + ':' + right(x,2)