A. Some of you may be aware that NT3.51 requires a manual update to bring it up to the revised daylight saving schedule, subsequent to the standardization of Daylight Saving by the EC.

I had thought we'd caught most of this yesterday, but anyone who still has 3.51 machines which have reverted back to GMT already may wish to update these machines according to the instructions below.

The issue has arisen as 3.5x GMT zone was set to begin at the 4th weekend in October (this is usually standard) HOWEVER this year October has 5 weekends and as agreed with the various time organizations, some years back, GMT will begin again on the 5th weekend - October 30/31 1999.

However in 3.5x the time zone is still set to weekend number 4.

Q156084 is the basics. Basically the registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time
Zones\GMT\TZI needs to be:

0000000000000000C4FFFFFF00000A00000005000200000000000000000003000000050001
00000000000000 - note the first 5 in the string was originally a 4

This then needs to be changed in:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\StandardStart - so change the 4 to a 5.

The most consistent way for changes to take effect is then to REBOOT.