[Ham-Computers] More on Daylight Time on March 11

[jandlmiller at bellsouth.net]

Thanks to all of you who responded to my recent post on this subject. This note will summarize and cause this information to archive for this list.

Recall that the provisions of the Energy Policy Act of 2005 caused daylight savings time start and end dates to change. That federal law provides that daylight time commences three weeks earlier and ends one week later, effective in 2007, than did the daylight savings time law that was in effect from 1987 to 2006.

Recall also that the life cycle for Win98SE and Win95B ended before the new daylight savings time law commenced on March 11, 2007. Accordingly, Microsoft has no patch to adjust the date/time function of unsupported computers. Therefore, unless user modifications are made the Win98SE and Win95B computer will continue to spring forward too late and fall back too early, just as the system registry tells it to do, but not in accordance with the new law.  More mischief is possible, if you had the box checked to automatically adjust your system clock for daylight time.

There are several ways for the user to fix the problem:

1. Spring forward and fall back. Manually set the computer clock ahead an hour on the new law start date on March 11, 2007 and every daylight start date thereafter.  Manually set the computer clock back an hour on the new law end date of November 4, 2007 and every daylight end date thereafter. For some users this is a perfectly acceptable activity and for some it is a royal pain.

2. Check Start--Settings--Control Panel--Date/Time. Uncheck the box "Automatically adjust clock for daylight savings changes." If left checked, the system registry will do exactly as it has been told to do and your clock will move ahead an hour in April and back an hour in October, not in accordance with the new law.

3. If you use the free program NISTIME-32.exe from the National Institute of Standards and Technology (NIST) in Boulder, CO (formerly the National Bureau of Standards) to reset your Win98SE and Win98B clock to an accuracy of about 10 ms from one of several Internet severs across the US, DON'T do 1. and 2 and  and think you've solved your problem.  Your problem willnot have been solved if you use this program and stop here.

NISTIME-32.exe is written to interface with the OS above and that includes the registry.  If you manually change the clock one hour ahead on March 11, 2007, then run NISTIME, that program will correctly report that you are one hour ahead of the specified offset from GMT(UTC) on that date.

Instead, go to Start--Settings--Control Panel--Date/Time.  Change the time zone in which the computer will be operating to the next time zone east toward the Greenwich meridian.  Therefore, Eastern becomes Atlantic, Central becomes Eastern, Mountain becomes Central, and Pacific becomes Mountain.  If you are west of the Pacific zone make the appropriate change.  In you are in certain states with separate practices within the state, or even separate customs at the county level (such as Indiana), be careful.

Once this zone change is made you will be able to use NISTIME without making any further adjustment.  You will not need to worry about resets in the spring or fall.  But be certain you ALSO uncheck the box  as described in 2. above.

4. For some however, any of the steps above will be unacceptable, and are too much like bailing wire and bubble gum fixes.  These folks will want to fix the system registry to redefine the start and end dates for daylight time in accordance with the new daylight savings time law.

Although there is much information on this subject available online from Microsoft and other sources, an individual who is no stranger to this list suggested I go to:

http://www.uic.edu/depts/accc/systems/daylight/windows.html

At this University of Illinois at Chicago site you will find what I believe is one of the most complete packages on this subject that I have seen.  This link will send you to Windows details, but at the top of the page you can choose Mac, Unix, and PDA's.

You will be looking for TZEDIT.exe the Time Zone Editor. This is the safest tool to use as you modify your system registry.  It's more desirable to use this tool from your original Windows installation CD, thereby avoiding possible download corruption that may cause you much grief later on.

On your original CD you should find TZEDIT. exe and TZEDIT.hlp.  You should find both of these files by following this path on the CD: D:\tools\reskit\config where D: is the CD drive.  Do yourself a favor and spend some time reading the short help file.  You will find there the name of the key that you will modify with TZEDIT and you be apprised that part of this key has information stored in binary, so you DON'T want to use REGEDIT, particularly when TZEDIT is already written to do the whole job for you.

Of course, if you don't have your original CD you can download TZEDIT from the UIC site.

The UIC site also has the detailed steps for you to use as you approach this task.  Read them carefully and deliberately and do a trial run or two before you make the actual changes.  Between the help file and the UIC site information you will be well prepared.  Using TZEDIT you will find a Cancel button for each screen, enabling you to back out of everything before you are ready to actually make the changes.  

Note the instruction in the UIC material, Step 6. regarding the need to repeat the changes you make for each time zone.  If you carry a laptop between Pacific and Eastern you will have more than one change to make.

As mentioned in UIC Step 7., 8., and 9. and more fully explained in the help file (see Editing the Time Zone Entry for the Current Time Zone), you are dealing with changes to more than one location in the system registry.  Be certain you fully read and understand the material before deciding that your work is complete.

If you elect to modify the system registry, and if you also use NISTIME-32.exe, you may want to run the time setting program as proof that you've done your system registry work correctly.  Commence at Start--Settings--Control Panel--Date/Time.  Set the time zone for the one in which the computer is now running.  Check the box to enable the automatic daylight time adjustment.  Run NISTIME.  If all was done correctly your computer system time will be adjusted to the atomic standard.

Good luck!

John W0IKT