cumulative time in excel

[Guest]

I am trying to format a cell that will add all of the times I input in a
vertical column. Those cells are in [h]:mm so that it can exceed 24 hours. It
all works well except when I try to enter a negative value into the equation.
If I add 10 minutes in one cell to 30 minutes in another cell, and then have
another cell that has -5 minutes, my total time does not equal 35 minutes.
Any suggestions?

 

[Ron Rosenfeld]

I am trying to format a cell that will add all of the times I input in a
vertical column. Those cells are in [h]:mm so that it can exceed 24 hours. It
all works well except when I try to enter a negative value into the equation.
If I add 10 minutes in one cell to 30 minutes in another cell, and then have
another cell that has -5 minutes, my total time does not equal 35 minutes.
Any suggestions?

What do you get for a total time?
How are you getting the negative time?
Are you using the 1900 or the 1904 date system?

I cannot reproduce your problem here. When I enter:

A1: 0:10
A2: 0:30
A3: =-TIMEVALUE("0:05")

A4: =SUM(A1:A3) --> 0:35


I cannot enter a negative time directly, hence that entry in A3 to get the
negative time in there. It could also be the result of some formula.

Also, if you are using the 1900 date system, negative times will display as
#############


--ron