Does your computer display the accurate time?

Zatni Arbi, Columnist, Jakarta

Still remember the old days when there was only one clock in your house? If you or any other member of the family wanted to know what time it was, you had to go to the living room where your grandfather's grandfather clock stood.

If someone forgot to wind the mainspring, the clock would stop and nobody would be able to tell the time.

Some older mechanical clocks used a weight and a pendulum to keep them tick-tocking. As with the spring clock, someone would have to raise the weight regularly to keep the clock working. It is just amazing how people in the 17th century were able to build mechanical clocks such as these ones.

Historians say that human beings in ancient civilizations started making clocks to tell the time of day around 5,000 to 6,000 years ago. Sun dials were used by the Egyptians in 3500 BC to divide the day into chunks of time approximating the hours that we now use.

Today, the days of sun dials -- and even mechanical clocks -- have long passed. You may still find them in old castles, mansions or public buildings, but they serve more as decoration rather than a true timepiece. Mechanical clocks were replaced by electric, then by electronic clocks. Then came quartz and quartz crystal technologies, which were then used in clocks and watches.

Today, almost every room in the houses of average people have a clock. We may not have learned how to be on time for our appointments and deadlines, but for sure we do have far more timepieces in our lives than our great grandparents did.

Our computers also have their internal clocks. That is why there are differences between a Pentium III 550 MHz processor and a Pentium 4 3 GHz processor. In the past, the motherboard would have a small battery to provide the PC's internal clock with power when it was powered down or its cable was pulled out of the socket.

A clock on a PC screen first became popular with the arrival of the Microsoft Windows operating system. At that time, a lot of people still had no idea what a graphical user interface (GUI) was, but they were excited to see a clock with moving hands displayed on their screens.

Now, with a dozen quartz clocks and two dozen quartz crystal watches in your house, do you really know for sure what time it is? Roughly, yes, but maybe not precisely.

Throughout the world there are atomic clocks that are intended to maintain the most accurate time on earth. The U.S. National Institute of Standards and Technology has a few of them. The question is, how can you set your PC clock so that it shows their time? You can download a piece of software from their website (http://nist.time.gov/problems.html), which will do it for you.

There are other sites on the Web that offer similar software for free. One of them is the Atomic Clock Sync Version 2.5 that you can download from World Time Server.com (www.worldtimeserver.com). The software can be set to check the time and adjust the PC's internal clock regularly, although in many cases it may mean an adjustment of 0.0004 seconds.

By the way, the good thing about World Time Server is that it can also tell you what time it is at this moment in other places, such as in Helsinki or in Johannesburg. So, before you make that call to your friend in Vancouver, check first what time it is over there.

Try the software, and you may be surprised to see how much your PC clock has strayed from the universal clock. And then you can set all the clocks and watches in your house, cars, calculators, PDAs, organizers, cordless phones, cell phones, microwave ovens, radios, TVs, remote controls, accordingly.

More important than knowing the most accurate time in the world is perhaps not to waste your time and other's time.