Found Solution:

Added DateDiff to statement

MonthlyDays: IIf(IsNull([ReleaseDate]),(IIf([DatePlaced]>=[Current Month:],[Next Month:]-[DatePlaced],[Enter Number of Days in Spreadsheet Month:])),(IIf([DatePlaced] And [ReleaseDate]<[Current Month:],0,(IIf([DatePlaced]>=[Current Month:],[ReleaseDate]-[DatePlaced],DateDiff("d",[Current Month:],[ReleaseDate]))))))

Additional Information:

Access 2002 - Comb Box Information:

Find a record on my form based on the value I selected in my combo box.

Control Source: Case#

After Update: [Event Procedure]

MS Visual Basic...