For the past week we’ve had this strange situation where all of the XP and Vista machines kept jumping ahead by an hour. Our domain controllers for our Windows network were correct along with any older OS’es we had in the office but the XP machines and Vista machines…they just couldn’t seem to get it straight.
This turns out to be one of those times where we had it backwards. The XP and Vista machines were correct…sort of. Since Bush decided to change the Daylight Savings Time date, the information stored in the OS for when DST started was incorrect. Patches were released for XP and 2003 machines and I assume that Vista had the correct information built in already and therefore didn’t need patching. What didn’t happen, was Microsoft didn’t patch W2K, which is what our domain controllers happen to be running.
Our network admin, not knowing this fact, came in and updated the time on these machines assuming correctly that the rest of the office would follow suit and we would all be running on the same times. What actually happened, is that when we updated the time on the domain controllers, which currently think they are not running under DST rules, the time was broadcast via NTP to all the domain members and each machine updated their clocks accordingly. However, when the newer machines updated their clocks, they assumed correctly that they were running on DST and added an hour to the time broadcast by the domain controllers which was actually correct but hand’t factored in DST. So all the newer machines were now an hour ahead.
The following article has links to KB articles that walk you through making the necessary changes to the registry for Win2k machines. As soon as we have finished this process i’ll post the results here.