Here is a reprint of the Mail on Sunday article published on 14 March 2004. The article is largely accurate except that the sundial does not work "anywhere in the world" - it will not work in the tropics and I have yet to produce one for the Southern Hemisphere, though that should be easy in principle. Look out for the amusing typo - you will be pleased to know that I do not "peddle" anything but I do enjoy "pedalling"! And finally, please do note that the £4.50 quoted does not include postage and packing - see the order forms for more details.

High-flyer with time on his hands

Throw away your clocks and calendars and replace them with a portable sundial that gives the time and date.

Research engineer Mike Knee is the inventor of the custom-made sundial. Instead of the traditional metal pointer mounted on a block of stone, Mike's design is made from paper and is the size and shape of a large ice-cream cone.

It is placed, pointed end down, in a glass on a windowsill. A pencil stands in the centre, its tip level with the top of the cone. When the sun shines through the window, the shadow cast by the pencil tells the time against vertical lines printed on the inside of the cone, much like a standard sundial.

But because the sun travels across the sky at varying heights at different times of year, the pencil's shadow lands on horizontal lines inside the cone at different levels, indicating the date.

In the height of summer, with the sun riding high in the sky, the light strikes the pencil at a sharp angle, casting the shadow on the cone at a lower level.

In winter, when the sun is closer to the horizon, the shadow shifts higher up the cone.

Mike, of Petersfield, Hampshire, says: "It was just a fun idea at first.

"Children love watching it to see where the shadow lands and then reading out the date. But it's also educational, showing them the path that the sun takes as it crosses the sky"

Mike, 44, was staring at the stars when he came up with the idea for his invention.

Mike had been peddling through the Hampshire countryside on a recumbent bicycle, a vehicle on which the rider lies back. As he looked up at the moon, stars and sun still visible in the early evening, he thought about the earth's place in the solar system.

Then he spent more than 12 months developing a computer program to produce a sundial that would work anywhere in the world.

When he receives an order, he taps the customer's address into a computer. A bespoke sundial is then produced ready for use at the exact longitude and latitude of the customer's home.

Mike has sold about 200 of them for £4.50 each, donating the proceeds to charity.

He would like someone to take his invention to greater commercial heights.

"I'm no entrepreneur," he admits, "but I would be interested in developing the idea"

©Mail on Sunday. This article was published in the Financial Mail on Sunday on 14 March 2004 and is reproduced here by permission.