Sub CalculateDateDifference()
'Graham Mayor - https://www.gmayor.com - Last updated - 22 Oct 2021
Dim xStartDate As Date
Dim sDate As String
Dim xEndDate As Date, dTestDate As Date
Dim xDay As Long, lCount As Long, i As Long, j As Long
Dim vHolidays As Variant

    vHolidays = Array("01/10/21", "02/10/21", "30/10/21")
    On Error Resume Next
    xEndDate = Date
    sDate = InputBox("Enter the start date", "Start Date", "")
    If IsDate(sDate) = False Then
        MsgBox "Please input a valid date.", vbInformation, "Date Calculation"
        Exit Sub
    End If
    xStartDate = CDate(sDate)
    If xStartDate > xEndDate Then
        MsgBox "The start date must be before the end date!", vbInformation, "Date Calculation"
        Exit Sub
    End If
    xDay = DateDiff("d", xStartDate, xEndDate)
    lCount = 0: dTestDate = xStartDate
    For i = 1 To xDay
        If Weekday(dTestDate) > 1 And Weekday(dTestDate) < 7 Then lCount = lCount + 1
        For j = 0 To UBound(vHolidays)
            If dTestDate = CDate(vHolidays(j)) Then
                lCount = lCount - 1
            End If
        Next j
        dTestDate = dTestDate + 1
    Next i
    MsgBox "There are " & lCount & " work days from " & xStartDate & " to " & xEndDate & vbCrLf, vbInformation, "Date Calculation"
End Sub