Don't know why you're getting that message but here's another way to write
that formula:

=MOD(D4-C4,1)

Or:

=D4-C4+(C4D4)

--
Biff
Microsoft Excel MVP


"squack21" wrote in message
...
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].