I realized that I was lacking a field with a constant date. So, I added a field that would have the current month. I used that date instead of the combo box. I figured that was my problem. I changed the code to this and now it works. Thanks for the assist. It helped a lot.

Dim X As Integer
Dim S1 As String, S2 As String

For X = 1 To 42
S1 = "Date" & X

S2 = "Day" & X

If Month(Forms!frmSchShiftCalendar(S1).Value) <> Month(Calendar) Then
Forms!frmSchShiftCalendar(S2).BackColor = &HD8D8D8
Forms!frmSchShiftCalendar(S2).BackColor = &HFFFFFF
End If

Next X