Private Sub Worksheet_SelectionChange sous conditions

        If ActiveCell.Value = 0 Then
            Application.EnableEvents = False
        Else
            Application.EnableEvents = True
        End If

Range("A:A")

Range("A1:A10")

Private Sub Worksheet_Change(ByVal Target As Range)
Dim Sh As Worksheet
  If Intersect(Range("J3"), Target) Is Nothing Then Exit Sub
  For Each Sh In Worksheets
      If Sh.Range("E1").Value = Target.Value Then
         Sh.Activate
         Sh.Range("A1").Activate
      End If
  Next Sh
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Count > 1 Then Exit Sub
    
    If Not Application.Intersect(Target, Range("G9:G" & Range("G" & Rows.Count).End(xlUp).Row)) Is Nothing Then
        Réponse = MsgBox("avez-vous changé le deshydrateur", vbYesNoCancel, "echeance deshy")
        If Réponse = vbYes Then
        Range("A5").Select
            'ma macro qui finit par activecell.clearcontent pour pouvoir remplir ma cellule"
        ElseIf Réponse = vbNo Then
        Range("B5").Select
        
            'ma deuxième macro qui finit par activecell.clearcontent pour pouvoir remplir ma cellule"
        End If
    End If
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Count > 1 Then Exit Sub
    Dim Saisie1 As Variant
    Saisie1=EDATE(RC[-1],12)
    
    If Not Application.Intersect(Target, Range("G9:G" & Range("G" & Rows.Count).End(xlUp).Row)) Is Nothing Then
    'j'annule l'application si ma cellule a déjà la formule + 12 mois par rapport à ma cellule de saisie d'intervention
           If ActiveCell.FormulaR1C1 = Saisie1 Then
           Application.EnableEvents = False
           Else
           Application.EnableEvents = True
           End If
           
           Réponse = MsgBox("avez-vous changé le deshydrateur", vbYesNoCancel, "echeance deshy")
        If Réponse = vbYes Then
           ActiveSheet.Unprotect Password:="juju"
       
           ActiveCell.FormulaR1C1 = "=EDATE(RC[-1],24)"
            
           ActiveSheet.Protect Password:="juju", DrawingObjects:=True, Contents:=True, Scenarios:=True _
        , AllowFormattingRows:=True, AllowSorting:=True
        
        ElseIf Réponse = vbNo Then
        ActiveSheet.Unprotect Password:="juju"
        ActiveCell.Select
            With Selection.Interior
        .Pattern = xlSolid
        .PatternColorIndex = xlAutomatic
        .ThemeColor = xlThemeColorAccent3
        .TintAndShade = 0.399975585192419
        .PatternTintAndShade = 0
    End With
     ActiveSheet.Protect Password:="juju", DrawingObjects:=True, Contents:=True, Scenarios:=True _
        , AllowFormattingRows:=True, AllowSorting:=True
           
        End If
    End If
End Sub

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim valeurG As Date, valeurH As Date
    Dim cellH As Range
    Dim Réponse As Integer
    
    If Target.Count = 1 Then
        If Not Application.Intersect(Target, Range("G9:G" & Range("G" & Rows.Count).End(xlUp).Row)) Is Nothing Then
            'j'annule l'application si ma cellule a déjà la formule + 12 mois par rapport à ma cellule de saisie d'intervention
           valeurG = Target.Value
           Set cellH = Target.Offset(0, 1)
           valeurH = cellH.Value
           If valeurH <> DateSerial(Year(valeurG) + 1, Month(valeurG), Day(valeurG)) Then
                Réponse = MsgBox("avez-vous changé le deshydrateur", vbYesNoCancel, "echeance deshy")
                If Réponse = vbYes Then
                   ActiveSheet.Unprotect Password:="juju"
                   cellH = DateSerial(Year(valeurG) + 2, Month(valeurG), Day(valeurG))
                   ActiveSheet.Protect Password:="juju", DrawingObjects:=True, Contents:=True, Scenarios:=True _
                        , AllowFormattingRows:=True, AllowSorting:=True
                ElseIf Réponse = vbNo Then
                    ActiveSheet.Unprotect Password:="juju"
                    ActiveCell.Select
                    With Selection.Interior
                        .Pattern = xlSolid
                        .PatternColorIndex = xlAutomatic
                        .ThemeColor = xlThemeColorAccent3
                        .TintAndShade = 0.399975585192419
                        .PatternTintAndShade = 0
                    End With
                    ActiveSheet.Protect Password:="juju", DrawingObjects:=True, Contents:=True, Scenarios:=True _
                        , AllowFormattingRows:=True, AllowSorting:=True
                End If   ' Réponse
            End If   ' valeurH <> DateSerial(Year(valeurG) + 1, Month(valeurG), Day(valeurG))
        End If  'Not Application.Intersect(Target, Range("G9:G" & Range("G" & Rows.Count).End(xlUp).Row)) Is Nothing
    End If   'Target.Count = 1
End Sub

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim valeurG As Date, valeurH As Date
    Dim cellH As Range
    Dim Réponse As Integer
    
    If Target.Count = 1 Then
        If Not Application.Intersect(Target, Range("G9:G" & Range("G" & Rows.Count).End(xlUp).Row)) Is Nothing Then
            'j'annule l'application si ma cellule a déjà la formule + 12 mois par rapport à ma cellule de saisie d'intervention
           valeurG = Target.Value
           Set cellH = Target.Offset(0, 1)
           valeurH = cellH.Value
           If valeurH <> DateSerial(Year(valeurG) + 1, Month(valeurG), Day(valeurG)) Then
                Réponse = MsgBox("avez-vous changé le deshydrateur", vbYesNoCancel, "echeance deshy")
                If Réponse = vbYes Then
                   ActiveSheet.Unprotect Password:="juju"
                   cellH = DateSerial(Year(valeurG) + 2, Month(valeurG), Day(valeurG))
                   ActiveSheet.Protect Password:="juju", DrawingObjects:=True, Contents:=True, Scenarios:=True _
                        , AllowFormattingRows:=True, AllowSorting:=True
                ElseIf Réponse = vbNo Then
                    ActiveSheet.Unprotect Password:="juju"
                    'cellH.Select
                    'Selection.Copy
                    'Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False
                    
                    ActiveSheet.Protect Password:="juju", DrawingObjects:=True, Contents:=True, Scenarios:=True _
                        , AllowFormattingRows:=True, AllowSorting:=True
                End If   ' Réponse
            End If   ' valeurH <> DateSerial(Year(valeurG) + 1, Month(valeurG), Day(valeurG))
        End If  'Not Application.Intersect(Target, Range("G9:G" & Range("G" & Rows.Count).End(xlUp).Row)) Is Nothing
    End If   'Target.Count = 1
End Sub