Adding IFERROR to a formula to get rid of #####

I am calculating time elapsed by subtracting one set of date/time from another, but when one of more of the cells for the date/time are blank, I want to return a blank in the time elapsed cell instead of the ####### that is currently populated. Below is an example of the formula that I am currently using.

=((N2+O2)-(D2+E2))

I have tried adding IFERROR several ways and have not figured out how to get this to work. Of course, I know that I also need to add ,"" somewhere along the line.

It's because if I recall correctly, ####### is not an error. Could it be that the number is too big to be displayed?

You're right Jdevil, ####### is NOT an error.
It means either the value is too long to display in the available width of the cell, OR
It's a Negative Time Value (Excel doesn't understand negative time, there's no such thing since we can't go backwards in time).
I think it's the negative time issue since the OP says the calculation is for elapsed time.

So to make it return blank instead, Try
=IF((N2+O2)-(D2+E2)<0,"",(N2+O2)-(D2+E2))

Thank you - Jonmo1, the formula you provided works! I don't think I stated that the ##### was an error, but I guess it was implied when I was trying to use the IFERROR.
Thanks again!

You're welcome.

I did just notice that you said

but when one of more of the cells for the date/time are blank

That isn't necessarily the same as if the resulting calculation is negative. Which is what the formula I posted tests for.

To test specifically for 1 or more of the cells being blank, try
=IF(COUNT(D2,E2,N2,O2)=4,(N2+O2)-(D2+E2),"")

Thank you again. I tried your "new" formula, but the first formula you provided was the one that actually worked/works.

I am calculating how long it takes someone to respond to a service call. So the call is made at date (D2) and time (E2) and the person arrives at date (N2) and time (O2). Sometimes they forget to put the call time/date or the arrive time/date in the log. As I drag the formula down all of the rows, what was happening was that if any of those four cells were blank the result would be ######, etc. With the first formula, if one of those four cells are empty, it leaves the calculated cell (time elapsed) blank, and still correctly calculates time elapsed for the other rows where all four cells are populated.

Hope this makes sense! Thanks again

You're welcome.