One way:

Change your workbook's date system to the 1904 system
(Tools/Options/Calculate, check the 1904 date system checkbox). The
WinXL default 1900 system can't display negative time values.

In article ,
"Arhippa" wrote:

How I'm able to calculate 5 hours 15 minutes minus 6 hours 30 minutes equals
-1 hour 15 minutes?