About the Clock Check Demo

The local time is taken from your local system clock. This is the time from the computer's operating system.

The standard time is taken from the server at the web site which is maintained at standard time.

The difference in seconds is the difference between standard time and local system time.  Your clock is 'fast' if you are ahead of standard time and 'slow' if your clock is behind it.

The difference is given in minutes or hours depending on the magnitude.

The drift is calculated from the previous reading made from the same computer on a previous day as determined by the GMT time.  Previous readings are stored locally as cookies and are recalled when the demo is run.

Drift is calculated from:

     Net Difference (seconds) /  Interval (days)

to give clock accuracy in terms of seconds of time that are lost (negative) or gained (positive) in a 24 hour period.  The drift gives an indication of how accurate your system clock is and how often it needs to be adjusted.

Last reading shows the last time you ran the demo and a reading was stored.  The demo will store only a single reading each day.

The accuracy of this test is approximately  +/- 5 seconds (remember it's a demo).   For a more accurate test, download and install our ClockWatch program to your computer and run it. 

Unlike our ClockWatch product, the time will not be corrected on your computer.

How it Works:

1. The demo stores the local time and standard time in GMT format.
2. User presses 'Calculate Results' and the times are passed to the calculation program.
3. The calculation program determines the difference in seconds between standard and local time
4. The calculation program checks for previous time readings made for the user.
5. The calculation program determines the drift of the computer clock  by comparing the current reading to the most recent reading taken in past visits.
6. The results are displayed and all previous readings are shown. No time correction is made.
7. The current reading is saved as a cookie for use in future visits.

Back to Demo Page

For more information see:

FAQ on Time and Time Standards

History of Timekeeping

FAQ on PC Clocks

ClockWatch Product Information