A. From the Control Panel Date/Time applet, select the Time Zone
tab to set the local country and its associated time difference. You can select the same tab to enable daylight saving.
Changing these settings updates the registry values under the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation key. I’ve listed the most useful time-zone values below.
| ActiveTimeBias |
This value is the current time difference from Greenwich Mean Time (GMT) in minutes and is the difference for GMT. For example, if you’re 1 hour ahead, GMT is 1 hour behind. The value would be ffffffc4, which is hexadecimal for -60. |
| Bias |
This value is the normal time difference from GMT, excluding daylight saving in minutes. The value is the difference for GMT, so if you’re 3 hours ahead (e.g., if you live in Moscow), the Bias would be ffffff4c, which is hex for 180. If you’re 2 hours behind GMT (e.g., if you're on a boat in the mid-Atlantic Ocean), GMT is 2 hours ahead, so the value is 120. |
| DaylightBias |
This value is the time difference used for daylight saving for GMT. If you're 1 hour ahead, the value is ffffffc4, which is hex for -60. Notice that the ActiveTimeBias is the sum of Bias and DaylightBias in daylight saving months, which is the same as Bias for standard months. |
| DaylightName |
The OS uses this name during daylight saving months. |
| StandardName |
The OS uses this name during non-daylight saving months. |
| DaylightStart |
This value tells the computer when to start daylight mode. |
| StandardStart |
This value tells the computer when to start standard mode. |
| DisableAutoDaylightTimeSet |
This value exists only if you clear the checkbox for the option Automatically adjust clock for daylight saving and if you set the value to 1. |
Using the Microsoft Windows 2000 Resource Kit or the Microsoft Windows NT Resource Kit reg.exe utility, you can use the following command to query these values from the command line:
C:\>reg query hklm\system\currentcontrolset\control\timezoneinformation\bias
REG_DWORD bias 0
C:\>reg query hklm\system\currentcontrolset\control\timezoneinformation\daylightname
REG_SZ daylightname GMT Daylight Time
End of Article
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Register
I export the string and edit the .reg file, cause I want to enable automatic daylight time setting. I do this by changing the value from "00000001" to "00000000", save it and add it by double clicking. Trouble is, it doesn't put it in effect. I know this, cause when I adjust date and time, the DST is checked - and when I click "OK" it adds an hour! And it only happens when I have the timezone tab active!
Now, as far as I have understood, the checkmark does not change system time, it adds an hour to it in Windows 2000. This means the time shown in my system tray should be actual time +01:00 when DST is put active. How do I get my system to acknowledge this, without entering "Date & Time", changing tab and then clicking "OK"?
A lot of work, just to change a setting. Well, not if you could automate the process for 100 clients during logon. My users would not be able to understand the process of changing this setting, so I need this solution badly.
Christen Stephansen April 07, 2003