Excel OnChange event

Question

I want to update a cell with the date-time when a value is entered to another one so,

How can i change the value of the B column to the date-time when a value is e

Answer 1

You could have tried this by yourself, couldn't you?
In my opinion, the hardest part was to think about the Change event.

Private Sub Worksheet_Change(ByVal Target As Range)    
If Intersect(Target, Range("A:A")) Is Nothing Then Exit Sub
Application.EnableEvents = False

ActiveSheet.Cells(Target.Row, 2).Value = Format(Now, "h:mm")
Application.EnableEvents = True
End Sub

You can change the Format content to whatever you need.