My system clock is an extra (extra) hour ahead during BST/ daylight saving

Question

I have a problem when my Windows 7 64-bit laptop is used during BST (British Summer Time)/ daylight saving periods.

Instead of the +1 shift in time, the system clock shifts +2 hours and can be a few minutes out from the NTP server time.

I've used all servers listed in the NTP server list - it makes no difference. I've just tried using pool.ntp.org, but I'm not convinced trying that is going to solve my problem, either.

From what I've seen, this is an issue that affects other Windows 7 users in other time zones, so it's not exclusive to GMT/BST users or users of a particular NTP server. My assumption is that it's something obscure in Windows 7 that's causing this issue.

Is there a fix for this issue? I've seen the issue described in questions and various articles online - but I haven't found a definite fix.

Solution

I tried my manufacturer's OEM distribution of Win7 Ultimate, rather than a generic OEM version, having had to reinstall it. So far, I've not had the date jump ahead an hour! How odd.

Comments

[harrymc]

Preliminary question : Which timezone is your computer on ?

[James]

(UTC) Dublin, Edinburgh, Lisbon, London is the current time zone.

[OmnipotentEntity]

Do you have another copy of an operating system installed?

[James]

Nope. It was the only one on the system when the problems started occurring. Anyway, it's 'fixed' now.

[Peanut]

I'm having this same issue now, can't find anything about it online though.

[James]

Thanks for the reply. All available updates are installed and so far as I can see, there aren't any additional KB updates on the MS site for this issue on Win7. Auto synchronisation is always set. The problem isn't hardware-based - before BST is in effect, the system time is managed fine. Just to clarify, when the system time is ahead and out of sync by a couple of minutes, I can update the time from the NTP servers and the problem is fixed. It recurs randomly, though (eg, a few days later).

[James]

Almost certainly after a boot - but not all boots. That said, I've noticed whilst the machine's been on for a few hours. Whether it changed at boot or some other time during the machine's operation, I don't know. How it gets out of sync by a couple of mins is a mystery to me. I think I tried unticking the sync option last year which, from memory, didn't make a difference. I've tried it again today, to double-check that it doesn't make a difference. Like I say, this seems to be an issue that isn't confined to me - others have reported it, too.

[James]

I'll check the BIOS time. I was under the impression that Windows controlled the BIOS time. I'm doubtful that this is a CMOS battery issue, as until BST kicks in, the laptop has never had a problem running in sync.

[harrymc]

I don't really think so either, but a problem can always arrive at the wrong time.