This goes into the worksheet's _Change event code. To get there, right-click
on the sheet tab and choose [View Code] from the list.

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address < "$A$2" Then
Exit Sub
End If
Range("A3") = Now()
End Sub

If you need to deal with cells other than A2 and A3, then we need to know a
little more about how your worksheet is laid out.

"chongcc" wrote:

I am try to automatic update a date cell when the target cell changes.
A1 is what I need, A2 is what I had, A3 is the inventory date. I want to
made it whenever A2 change, A3 will automatic update to the current date. If
not, A3 should stay unchange with the last inventory date.

Thanks in advance for your help.