You can change to the 1904 date system under Tools >
Options, but do so cautiously. To learn more, see:
http://www.cpearson.com/excel/datetime.htm#AddingTimes
The method I prefer is to subtract the 2 times (you can
still use negative time values in calculations, you just
can't see the result), hide the cell, then use another
cell to display the negative time as text. See:
http://tinyurl.com/5l2bx
HTH
Jason
Atlanta, GA
