[ntp:questions] Re: Windows timekeeping

Bryan Henderson bryanh at giraffe-data.com
Sat Aug 5 15:42:25 UTC 2006

>Windows assumes that the RTC on the motherboard is set to local time, as 
>it would typically be set from someone's watch when it is first set up by 
>an individual user (it may be set to Chinese or Taiwanese time when first 

I don't follow this part.  The user uses Windows to do this setting,
right?  So Windows could choose any timezone for the hardware clock,
and UTC would be a natural choice.  Windows obviously asks the new
user what time zone he's in, and therefore when the user says what
time his wristwatch says, Windows knows what UTC that corresponds to.

But I do believe that Windows systems still use local time, because I
hear about people who run Linux and Windows on the same hardware and
therefore Linux's 'hwclock' has to understand that the hardware clock
is in some local time.

Maybe it's just a backward compatibility thing; at one time you might
have wanted to switch between old and new Windows on the same
hardware.  In fact, it's always been 'hwclock' default (though
discouraged and usually overridden) to use local time, for the same

Bryan Henderson                                    Phone 408-621-2000
San Jose, California

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