Need help - calculating daily, weekly, and monthly totals based two dates and networkdays

Ive been looking at it, no doubt its possible within a formula its just an awkward one because you have this period of "free days" as such. Its getting the logic of how that works which is causing the issue.

No doubt it'll be something fairly simple but not got it yet!

Add this function and then call it (referncing your Days cell) from the Months cell. ie in J13 put =CalcMonths(E13)

Function CalcMonths(inDays)
outMonths = 0
outweeks = 0
outdays = 0
Do Until inDays = 0
    outdays = outdays + 1
    Select Case outdays
        Case Is = 3
            outweeks = outweeks + 1
            outdays = -1
        Case Is > 5
            outdays = 0
        End Select
        Select Case outweeks
        Case Is = 3
            outMonths = outMonths + 1
            outweeks = 0
            outdays = -11
    End Select
    inDays = inDays - 1
Loop
If (outdays < 0) Then
outdays = 0
End If

CalcMonths = outMonths & ":" & outweeks & ":" & outdays
End Function

Can you test that to see if it gives right results? we can then look at the format of output from there.