> An oddity! Last week, my clock suddenly lost an hour and when I mentioned > it to someone, they thought I had forgotten to tick the box which allows > automatic date changes twice a year. I had NOT forgotten and the clock had > gone forward one hour on the appointed day - but then back again a few days > later. Anyway, I duly altered the clock setting and all was well. > > Early this morning when I sent out email messages, the clock was still > correct, but now I want to use the computer again, I notice the clock has > gone forward one hour. > > I have been out shopping for a couple of hours and the computer was NOT > turned off. All I did was turn the monitor off before I went out. > > I find this rather puzzling but have heard of one other person suffering the > same trick. Is it a general fault somewhere - how many others have computer > clocks which are playing tricks? ( For cc: people, I work with Internet Unix servers, not Microsoft end-user PCs, so can't say what one has to click on MS-Inc. stuff, but can give some background that might enlighten ) IBM style PCs have an RTC (real time clock chip). The OS (operating system) asks the RTC the time each time the PC is turned on, & after that the OS (ie DOS/Win-95/8/Linux/Unix/FreeBSD/BeOS/ whatever) synchronises the 2 clocks to each other. The correction can go either way, from either clock to the other, depending how the programers feels appropriate: periodic, or event driven; to allow for example: crystal frequency drift, change of timezone (laptop in a plane), loss of RTC interrupts, while other device error messages display under poling, user manual correction, etc. Each time computers conect (including to Internet etc), there's a chance they be running time daemons to synchronise; computer nets elect or designate master daemons to synchronise other computers running slave daemons. I have a radio synchronised LCD clock that listens to Braunschweig (equivalent of Rugby Radio, linked to national atomic clock) ... (it plugs on a serial port, others can plug on a bus slot). ISPs/IAPs (Internet Service/Access Providers) either use radio clocks or time daemons synchronised as a slave to their backbone provider. My LCD clock adjusts for Summer time .... Summer time is a real pain: The BIOS (hardware) doesn't know about time zones or summer time: The OS doesn't necessarily remember if your BIOS was set during Winter or Summer time, unless you tell it. The OS only knows which time zone you'r in, 'cos you told it (or installed a customised national variant of world-purchasable software), or the OS guesses zone from EG the .uk terminal part of a domain name). Some people hope they'll be lucky 'cos they live in the UK (the lucky simple zone with the Greenwich meridian), but some software does not default to GMT (0 offset) but Pacific Standard Time (5/7 hours/whatever). Old versions of software may have been written to know about old dates for changing to summer time, that have since been changed by national governments. (Imagine the problem: over 100 countries worldwide, with many politicians everywhere debating the equivalent of whether it's better for school children to walk to school in the dark, or walk home in the dark etc; & changing their minds every so often; & trying to keep an OS with world wide usage, up to date with periodic local changes). Conclusion: It's most probably not a hardware problem, assuming the clock is jumping precisely one hour, it's most probably one piece of software not knowing how another piece is configured, WRT (with respect to) summer time. Where you start clicking under MS-Inc. I don't know, but don't forget first to hit Control+Al+Del, (or DEL at boot) & ensure your BIOS time is correct. Julian