Negative time is before the year 1900???
I think you want to change the format of the cell as a number (not a date).
The number will be fractions of days. It your job use this number properly.
You can add a negative number (-4) to todays date 4/6/07 and get 4/2/07.

when ever you add or subtract time the answer must be a number and not a
date or time. It doesn't make sense to subtract 4/7/07 - 4/6/07. The answer
in date time is actually 1/2/1900 because time in excel starts at 1/1/1900.
subtracting 4/7/07 - 4/6/07 is 1 and then you add 1 to 1/1/1900 and get
1/2/1900.


"santaviga" wrote:

Can anyone advise me if there is a way to calculate negative time in excel.

this is doing my head in, keeps returning ############

Regards