Macro for prompting date entry

Try this one

Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
    Dim r, c, u As Integer
    r = Target.Row
    c = Target.Column
    u = ActiveSheet.Cells.SpecialCells(xlLastCell).Row
    If c <> 5 And c <> 11 Then Exit Sub
    If r > u Then Exit Sub
    If c = 5 Then
        If VBA.UCase(Range("D" & r)) <> "PENDING" Then Exit Sub
    ElseIf c = 11 Then
        If VBA.UCase(Range("J" & r)) <> "PENDING" Then Exit Sub
    End If
    
    Dim Rng1            As Range
    Dim Prompt          As String
    Dim Title           As String
    Dim strDate1       As String
    Dim Date1 As Date
    
    Prompt = "Enter date formatted: mm/dd/yyyy"
    Title = "[Please Enter Date]"
    strDate1 = InputBox(Prompt, Title)
    
    
    On Error Resume Next
    Date1 = CDate(strDate1)
    If Err <> 0 Or strDate1 = "" Then
        Exit Sub
    End If
    On Error GoTo 0
    Target.Value = VBA.Format(Date1, "mm/dd/yyyy")
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)

    If Target.Column <> 2 And Target.Column <> 3 And Target.Column <> 8 And Target.Column <> 9 Then Exit Sub
    
    If Target.Column = 2 Or Target.Column = 3 Then
        If VBA.UCase(Range("D" & Target.Row)) <> "PENDING" Or Range("E" & Target.Row) <> "" Then Exit Sub
    ElseIf Target.Column = 8 Or Target.Column = 9 Then
        If VBA.UCase(Range("J" & Target.Row)) <> "PENDING" Or Range("K" & Target.Row) <> "" Then Exit Sub
    End If
    
    Dim Prompt          As String
    Dim Title           As String
    Dim strDate1       As String
    Dim Date1 As Date
   
    
    Prompt = "Enter date formatted: mm/dd/yyyy"
    Title = "[Please Enter Date]"
    strDate1 = InputBox(Prompt, Title)
    
    
    On Error Resume Next
    Date1 = CDate(strDate1)
    If Err <> 0 Or strDate1 = "" Then
        Exit Sub
    End If
    On Error GoTo 0
    If Target.Column = 2 Or Target.Column = 3 Then
        Range("E" & Target.Row).Value = VBA.Format(Date1, "mm/dd/yyyy")
    ElseIf Target.Column = 8 Or Target.Column = 9 Then
        Range("K" & Target.Row).Value = VBA.Format(Date1, "mm/dd/yyyy")
    End If
End Sub