In general, it's better to use a Number field to manage durations. You can
then sum them and present the results as a time as explained in this
article:
Calculating elapsed time
at:
http://members.iinet.net.au/~allenbrowne/casu-13.html
If you don't want to do that you could convert the times into minutes and
then sum them and format the results. Use DateDiff() to get the number of
minutes, e.g.:
DateDiff("n", #0:00:00#, [YourTimeFieldHere])
It is possible to simply sum the times, but will still hit problems when
they wrap past 24 hours, so you still have to DateDiff() and to reformat the
totals correctly. A couple of the MVPs wrote a more complete DateDiff that
may help:
http://members.rogers.com/douglas.j.steele/Diff2Dates.html
