Can I do this?

[Guest]

Example:
A1 is blank, B1 says 18:40:00, C1 is blank, D1 is set up to calculate
A1+B1-C1. right now D1 is showing 18:40:00. I want it to be blank until a
value is entered into A1. B1 is a constant value of 18:40:00. All cells are
formatted to show cumalative time(hhh:mm:ss). Is there a formula for this?

 

[JulieD]

Hi

in D1 enter
=IF(ISBLANK(A1),"",A1+B1-C1)

Cheers
JulieD

 

[Gordon]

Example:
A1 is blank, B1 says 18:40:00, C1 is blank, D1 is set up to calculate
A1+B1-C1. right now D1 is showing 18:40:00. I want it to be blank
until a value is entered into A1. B1 is a constant value of 18:40:00.
All cells are formatted to show cumalative time(hhh:mm:ss). Is there
a formula for this?

In D1, type =IF(A1="","",A1+B1-C1)