Thanks Guys,
I am afraid we are in darkest Africa here ( actually summer is upon us with wall to wall blue skies but no time standard signals that I know of in Cape Town )
Yes wasn't it Einstein who showed that two clocks will show the same time only if one is stopped, and thats only twice a day..
I think the existing mishmash of clocks are fed from different mains wiring circuits, or I could have had a simple pulse and phantom supply ring.
The budget is not much, so GPS is out of the question.
The guy knows I make LED displays, and I think he is looking for something cheap.
The range is max 30m, but I havnt seen the layout, perhaps I should go for a mesh type wireless setup.
I have just worked out a simple way of doing it with CMOS chips, 6 in each master and slave units ( excluding the LED drive chips which I would need for the Arduino anyway ) which would update the time every minute, and have a xtal clock.
But I really enjoy using the Arduino !!!