Adjustment for daylight savings time

[Howard Kaikow]

On a multiboot system, only 1 of the OS is set to adjust for daylight
savings time.
However, when I reboot to go to another OS and then return to the original
OS, the clock is getting set back again.

I'd like to check the setting in each registry.
Which registry setting do I need to check?

 

[Mark V]

On a multiboot system, only 1 of the OS is set to adjust for
daylight savings time.
However, when I reboot to go to another OS and then return to
the original OS, the clock is getting set back again.

I'd like to check the setting in each registry.
Which registry setting do I need to check?

If you must do this via registry instead of the provided
GUI (Adjust Date/Time) then
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
Should be the place. Use REGMON (Sysinternals) to see what gets changed
when you GUI-unckeck "Automatically adjust..."

I don't know the details offhand.

 

[Howard Kaikow]

Thanx.

Using the GUI is not doing the job.
Something is causing the time to change anyway

 

[Dan Seur]

Disassemble the BIOS clock code and see if that's the culprit.

 

[Mark V]

Thanx.

Using the GUI is not doing the job.
Something is causing the time to change anyway

Are two operating systems "warring" over this? Seen that. If both
do not reset the BIOS clock by an hour, and the BIOS does not itself
do a Time Change either, you should be good.

 

[Howard Kaikow]

the multiboot pc has 4 win 200s installed on c, f, g and j drives.
os on j is the main os.

i rarely use the others except for:

a. Each OS has a different version of Office (I need that for
writing/testing VBA macrros)
b. I have vb 6 enterprise on all 4, so I boot to the appropriate system to
compile VB with the appropriate version of office to make sure early binding
works.

last i checked, only the os on J was set to adjust the time.
AFAIK, the BIOS does not adjust the time.

I had ASSuMED that if I set only 1 of the OS to adjust the time, then
there'd be no problems.

I just downloaded REGMON, so I'll see what gets changed if I toggle the
option via the GUI on the J drive, then I'll boot to the other OS and see
what's in the registry.

Note that certain versions of Norton Auntie Virus cause an issue with the
time adjustment.
For example, several years ago (I forget which NAV version), NAV caused the
time to adjust on unexpected dates (and in either direction).

I was one of the first to report this in the old Symantec forums. Finally,
after a loooong time, Symantec came up with a "fix".

However, the "fix" was incomplete and is still evidenced today in NAV 2005.
NAV seems to cause Windows to NOT issue the message informing you that the
clock has been adjusted, even tho the clock has been adjusted. Why/how this
happens, I know not.

So it could be that NAV is somehow causing a problem.
The problem is not new, it's been going on for years.

 

[Howard Kaikow]

Bingo!
Found the problem!

The PC was originally purchased with OEM Win 98 installed on C drive.

Win 2000 was later installed as a clean upgrade to the F drive.

Later, I got really masochistic, and cloned Win 2000 on F to the G drive.
10's of thousands of registry/file edits, but I got it to work! NEVER will I
go thru that again!

Later, a clean install of Win 2000 was made on the J drive.
Most recently, the Win 98, on the C drive, was upgraded, in place, to Win
2000.

The OS on the J drive was set to adjust for daylight time.
The OS on C, F, and G were set to NOT adjust for daylight time.

In all 4 cases, the checkbox for the GUI for this option was set correctly.
However, the registry for the Win 2000 on the C drive had incorrect settings
for DaylightBias, even tho the checkbox in the GUI was cleared.

So, I tried checking, then unchecking the option via the GUI.
When I checked the registry, I found that the value for the
CurrentControlSet had been now set correctly, BUT, and I do have a big butt,
the value for ControlSet2 was still incorrect. So I manually modified the
value.

I expect that this has fixed the problem.
Guess I'll find out in April 2006.

So I guess this was a bug in the Win 2000 that had been upgraded in place
from Win 98.