Sub Test_II()
Dim plageA As Range, plageB As Range, c As Range
Set plageA = Sheets("ep").Range("$D$7:$BC$7")
Set plageB = Sheets("ep").Range("$D$5:$BC$5")
With Application
.ScreenUpdating = False
For Each c In Range("C5:NC5")
MsgBox MonthName(Month(c.Offset(-2)))
If .CountIf(plageA, "a") * .CountIf(c.Offset(-3), "jeu") * .CountIf(Range("C1"), MonthName(Month(c.Offset(-2)))) * _
.CountIf(plageB, MonthName(Month(c.Offset(-2)))) * .CountIf(c.Offset(1), "a") Then
c.Value = 6
End If
Next
End With
End Sub