I tried all of your suggestions and I still get the same error message. I
should state that I am using Microsoft Office Professional Plus 2007. I am
wondering if displaying the time as military time would make a difference.
If someone would like I could send you a copy of the spreadsheet I am working
on to evaluate for yourself. Any and all help is appreciated.

"squack21" wrote:

This formula gives me a error message every time I enter something in the
worksheet: =D4-C4+IF(C4D4,1). It says Excel ran out of recourses and the
formula could not be evaluated. Originally I was lookin for a formula that
would calculate minutes of production time per shift. AM to PM and PM to AM.
I am formatting my start and stop time as h:mm AM/PM and my result of the
above formula as [m].