Hiya
RT
Can't email at the moment - Micro$hit OE is having hissy fit tonight so here it is in a nutshell:
Format the Beginning Time & Ending Time cells as a time format.
In the Time Interval column use the following formula
=IF(b1<a1,b1+1,b1)-a1
Cell 'A1' is beginning time
Cell 'B2' is ending time
These two cells and the time interal are formatted in ordinary 24:00 hr.
The only catch seems to be that the data entry by the users must use a colon ':' to separate hrs & minutes.
Hope it works OK for you.
T.