Input Data/Output data in separate sheets

maybe so (in the module of sheet "INPUT SHEET")

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address(0, 0) <> "B2" Then Exit Sub
Range("A2") = Range("A2") + Target
If Len(Target) Then Sheets("OUTPUT SHEET").Cells(Rows.Count, 1). _
   End(xlUp)(2, 1).Resize(, 2).Value = Array(Now, Range("A2").Value)
End Sub