Put timestamp when a checkbox is ticked or unticked - excel

Question

I have a worksheet with 3 rows and 7 columns (A1:G3).
A and B columns have 6 checkboxes (A1:B3). Boxes in columns A & B are linked to columns C & D respectively. Cells in columns E & F are just replicating columns C & D respectively (live E1 cell is =C1 and F3 cell is =D3).
I want to put a timestamp in cell G for each row when a checkbox is ticked or unticked by using Worksheet_Calculate event in VBA for that sheet.
My code works when used for just 1 row.
Private Sub Worksheet_calculate()
Dim cbX1 As Range
Set cbX1 = Range("A1:F1")
If Not Intersect(cbX1, Range("A1:F1")) Is Nothing Then
Range("G1").Value = Now()
End If
End Sub
I want to combine the code for 3 rows.
Here are 2 variations:
1st one:
Private Sub Worksheet_calculate()
Dim cbX1 As Range
Dim cbX2 As Range
Dim cbX3 As Range
Set cbX1 = Range("A1:F1")
Set cbX2 = Range("A2:F2")
Set cbX3 = Range("A3:F2")
If Not Intersect(cbX1, Range("A1:F1")) Is Nothing Then
Range("G1").Value = Now()
ElseIf Intersect(cbX2, Range("A2:F2")) Is Nothing Then
Range("G2").Value = Now()
ElseIf Intersect(cbX3, Range("A3:F3")) Is Nothing Then
Range("G3").Value = Now()
End If
End Sub
When I combine them with ElseIf like in the code above, a timestamp gets put in only G1, no matter if I tick B1 or C2.
2nd one:
Private Sub Worksheet_calculate()
Dim cbX1 As Range
Dim cbX2 As Range
Dim cbX3 As Range
Set cbX1 = Range("A1:F1")
If Not Intersect(cbX1, Range("A1:F1")) Is Nothing Then
Range("G1").Value = Now()
End If
Set cbX2 = Range("A2:F2")
If Not Intersect(cbX2, Range("A2:F2")) Is Nothing Then
Range("G2").Value = Now()
End If
Set cbX3 = Range("A3:F2")
If Not Intersect(cbX3, Range("A3:F3")) Is Nothing Then
Range("G3").Value = Now()
End If
End Sub
When I combine them by ending each one with End If and start a new If, timestamp gets put in all of the G1, G2 and G3 cells, even if I tick just one of the boxes.

Answer 1

You seem to be confusing Worksheet_Calculate with Worksheet_Change and using Intersect as if one of the arguments was Target (which Worksheet_Calculate does not have).
Intersect(cbX1, Range("A1:F1")) is always not nothing because you are comparing six apples to the same six apples. You might as well ask 'Is 1,2,3,4,5,6 the same as 1,2,3,4,5,6?'.
You need a method of recording the values of your range of formulas from one calculation cycle to the next. Some use a public variable declared outside the Worksheet_calculate sub procedure; personally I prefer a Static variant array declared within the Worksheet_calculate sub.
The problem with these is initial values but this can be accomplished since workbooks undergo a calculation cycle when opened. However, it is not going to register Now in column G the first time you run through a calculation cycle; you already have the workbook open when you paste in the code and it needs one calculation cycle to 'seed' the array containing the previous calculation cycle's values.
Option Explicit
Private Sub Worksheet_Calculate()
Static vals As Variant
If IsEmpty(vals) Then 'could also be IsArray(vals)
vals = Range(Cells(1, "A"), Cells(3, "F")).Value2
Else
Dim i As Long, j As Long
With Range(Cells(1, "A"), Cells(3, "F"))
For i = LBound(vals, 1) To UBound(vals, 1)
For j = LBound(vals, 2) To UBound(vals, 2)
If .Cells(i, j).Value2 <> vals(i, j) Then
Application.EnableEvents = False
.Cells(i, "G") = Now
Application.EnableEvents = True
vals(i, j) = .Cells(i, j).Value2
End If
Next j
Next i
End With
End If
End Sub