It's all in the timing

Do you know what time it is? Do you care? If I were to ask twenty people at random to tell me the correct time, I probably would get twenty different answers.

When I retired, I stopped wearing a wristwatch. I really didn’t care or need to know the exact time. But what if I were going to catch an airplane or, like this last weekend, take part in a contest that started exactly at one o’clock. Then the exact time would be important.

So, what do we mean by exact time and where do we get it? This really is a rather complex question but there are some practical answers.

In this country, the standard time clock is the responsibility of the U.S. Naval Observatory in Washington, DC. They and their counterparts at the Greenwich Observatory in the United Kingdom are responsible for setting the world’s clocks. The familiar Greenwich Mean Time is the master of all our clocks and we in California, during Pacific Standard Time, are exactly eight hours behind GMT. When the master clock in Greenwich reads noon, it is four o’clock in the morning here in Tustin.

One way we can check for our correct time is to look at our computers. In the lower right hand corner of a Windows computer, there is a clock indicator. But isn’t this just like a wristwatch? Doesn’t the time shown depend upon the internal mechanism of the computer? Yes, but in Windows XP, the story gets more interesting.

It is the responsibility of the U.S. National Institute of Standards and Technology, NIST, (the old Bureau of Standards) to make the correct time available to all users. They have a group of atomic clocks in Colorado that keep their clocks in synchronization with the clocks in Greenwich and Washington. They still broadcast standard time over the radio but now also make the correct time available over the Internet.

In Windows XP, clicking on the clock in the lower right hand corner brings up a screen that shows the computer clock. One of the tabs in that window says “Internet Time.” It shows that Windows is synchronizing your computer clock using the atomic clocks at NIST. If you think your clock is off a few seconds or even minutes, clicking on the “Update Now” button will resynchronize your computer’s clock.

Maybe we don’t give “time” much thought, but many things depend upon knowing correct time. Our TIVOs and VCRs get their time set when some television channels broadcast a time signal synchronized with NIST. After all, if we want to record a television show, we hope TIVO knows when to start recording.

Lloyd Denny came in the other day with a new wristwatch that gets correct time from a radio broadcast from Colorado and I have a large digital clock on my wall that also is synchronized with NIST.

So we are surrounded by time. It doesn’t make much difference if you come in on Friday five or ten minutes early or late, but maybe you don’t want to miss a meeting that starts “on time.”

If you would like to hear more about time keeping, or other computer topics, visit “Coffee and Computers” at the Tustin Area Senior Center, 200 S. ‘C’ Street, any Friday morning starting at (roughly) 9 a.m. Bring your questions or just come in and visit.

In the mean time, keep the neurons happy, synapses snapping and enjoy computing.

For Additional Information:

If you would like to check your clock, visit “”

You still can call the telephone number 853-1212 and get the good old time recording but there now might be a charge.

Visit “” (yes, that’s WWP) for Greenwich Mean Time.

For an explanation of Universal Coordinated Time, visit “”

Nerds can go to and search for “How Atomic Clocks Work.


Dr. Art Holub is a long time resident of Tustin and teaches computer and Internet courses at the Tustin Area Senior Center and the Tustin Adult School. Visit his web site at: This column is written to address the computer adventures and concerns of older adults. If you have comments, questions or suggestions for future columns, Email HIM at:

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