time interval math

I'm still working on getting this to work, but the summary is this:

I am getting several (many) intervals of hour, minutes and seconds. I need a
sum of the absolute value these intervals, similar to the SUM(ABS())
function for numbers; and I need to divide this sum by an integer (bigint).
Getting the intervals is no problem, but I can't find built in functions for
the rest. Currently on 8.3, want to upgrade to 9.x but I can't until this is
finished.

Do these functions exist, or will I be forced to convert to seconds, do the
math and then convert back to hour-minute-second format (I am assuming from
current data that, after the divide, the result should be in the minute:
second range).

Edward W. Rouse
Comsquared System, Inc.
770-734-5301