[ntp:questions] Re: simple time server

David J Taylor david-taylor at blueyonder.co.not-this-bit.nor-this-part.uk
Sat Aug 5 06:36:59 UTC 2006


Darren Dunham wrote:
[]
> I believe "specify a time zone" and "tell the kernel to change its
> clock" are equivalent on Windows.  Yes?

No.  Internally, all 32-bit Windows (from Windows NT in 1992 and Windows 
95 in 1995) keep time internally in UTC, and have the option via the 
regional settings to display time in "local time".  The local time offset 
can change between summer and winter as you wish.  All this is already 
built into Windows.  The internal timekeeping does not change when a 
time-zone is specified, just the time displayed to the user.  Much of my 
software, for example, which deals with satellite tracking, uses UTC 
throughout, and obtains this via a single system call to Windows: 
GetSystemTime

  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/getsystemtime.asp

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 
delivered).

Cheers,
David 





More information about the questions mailing list