I need to calculate two columns of time. Most entries fall within the
same day's 24 hour limit, so a simple forumla "=b1-a1" will do. But a
few in the 2nd column will cross midnight.

I could only find tips on formatting the result of such substracting in
the Excel Help file. The example used falls within the same day.

The example used in the Help file has both the date AND the time in the
same cell: "mm/dd/yy hh:mm." In both columns of mine, the time is
formatted as "hh:mm:ss" only. So I changed an entry to the same format
used in the Help file, which didn't seem to make a difference.

Thanks in advance,
Adam T.