Dois-je faire une "Loop" en VBA ou une formule ???

Sub Dates()
Dim rg1 As Range, rg2 As Range
Dim dateFin As Date, dateDebut As Date

Application.ScreenUpdating = False

'date de départ
Set rg1 = Sheets("Feuil1").Range("A1")
dateDebut = rg1.Value

'date de fin
dateFin = Sheets("Feuil1").Range("A60000").End(xlUp)

'écriture de toutes les dates
Set rg2 = Sheets("Feuil1").Range("D1")      'à changer selon où tu veux écrire les résultats
Do Until dateDebut = dateFin + 1
    rg2 = dateDebut
    dateDebut = dateDebut + 1
    Set rg2 = rg2.Offset(1, 0)      'ligne suivante
Loop

'écriture des congés
Set rg2 = Sheets("Feuil1").Range("D1")
Do Until IsEmpty(rg2)
   Set rg1 = Sheets("Feuil1").Range("A1")
   rg2.Offset(0, 1) = "0"            'valeur par défaut
   Do Until rg1 = rg2 Or IsEmpty(rg1)
        Set rg1 = rg1.Offset(1, 0)
   Loop
    If rg2 = rg1 Then
        rg2.Offset(0, 1) = rg1.Offset(0, 1)
    End If
Set rg2 = rg2.Offset(1, 0)
Loop

Application.ScreenUpdating = True

End Sub

Sub Ap_Classic()
Dim d As Date, f As Date, nbj&

f = [A65536].End(3)
d = [A2]
nbj = f - d
[C2].Value = [A2].Value
[C2].AutoFill Destination:=Range("C2").Resize(nbj), Type:=xlFillWeekdays
End Sub

Sub a_fun()
Dim d As Date, f As Date, nbj&
f = [A65536].End(3): d = [A2]
nbj = f - d: [C2].Value = [A2].Value: [C2].AutoFill [C2].Resize(nbj), 6
End Sub

=SI(LIGNE()>MAX(A:A)-MIN(A:A)+1;"";MIN(A:A)+LIGNE()-1)

=SI(D1="";"";SI(ESTNA(EQUIV(D1;A:A;0));0;INDEX(B:B;EQUIV(D1;A:A;0);0)))

Sub test()
mi# = Application.WorksheetFunction.Min(Range("A:A")): ma# = Application.WorksheetFunction.Max(Range("A:A"))
Dim v(), r As Range: ReDim v(1 To ma - mi + 1, 1 To 2)
For i% = LBound(v) To UBound(v)
    v(i, 1) = mi + i - 1: Set r = Range("A:A").Find(what:=CDate(v(i, 1)))
    If r Is Nothing Then v(i, 2) = 0 Else: v(i, 2) = r.Offset(, 1)
Next i
[C1].Resize(UBound(v), 2) = v
End Sub

Sub a_bis()
Dim d As Date, f As Date, nbj&
f = [A65536].End(3) 'dernière date en colonne A
d = [A2] ' première date
nbj = f - d 'différence en nombre de jours entre la 1ère et dernière date
[D2].Value = [A2].Value ' on donne à D2 la valeur de A2
[D2].AutoFill [D2].Resize(nbj + 1), 5
'ici on se sert en VBA de la copie avec le choix:
'Incrémenter les jours : 5= jours ; 6= jours ouvrés
End Sub

Sub a_TER()
Dim d As Date, f As Date, nbj&, r As Range, P$

Set r = Range([A2], [A65536].End(3))

f = [A65536].End(3)
d = [A2]
nbj = f - d

[D2].Value = [A2].Value
[D2].AutoFill [D2].Resize(nbj + 1), 5

P = r.Resize(, 2).Address(4, 4, xlR1C1)

With [E2]
    .Formula = "=IF(ISNA(VLOOKUP(RC[-1]," & P & ",2,0)),0,VLOOKUP(RC[-1]," & P & ",2,0))"
    .AutoFill Destination:=Range("E2").Resize([D65536].End(3).Row - 1), Type:=xlFillDefault
    .Value = .Value
End With
End Sub