Hello. My parents have got an ancient Smiths timer which controls some
outside lights. At the moment, no matter how the timer is programmed, the
lights are on all the time, unless the timer is actually switched off. Dad
used to fiddle with it and, miraculously, it did what he wanted. Now, for
some reason, it won´t.

The timer has an override button on the left. Then there's a row on three
buttons (hours, minutes, and set). Then there´s a vertical slider with S at
the top and N at the bottom. There's a window above the buttons where the
time appears.

Thanks for any suggestions.