[ntp:questions] Automatic time synchronization of local hw clock.

Rob nomail at example.com
Wed Apr 16 15:04:35 UTC 2014

Martin Burnicki <martin.burnicki at meinberg.de> wrote:
> Imagine what happens if you shut down Windows *before* DST starts and 
> reboot *after* DST has started? Your system time will be off by 1 hour 
> because standard time has been written to the RTC at shutdown, but DST 
> is assumed to be read from the RTC at boot time, while the RTC in fact 
> was still running at local standard time.

No, because Windows recognizes this condition and adjusts accordingly.

What really fouls things up, though, is when you boot Linux inbetween
and have the RTC set to localtime there as well.

I remember having read somewhere that there is a registry setting
in Windows to have the RTC in UTC as well, but it is not documented
in the usual Windows reference manuals.

Normally you can avoid these issues when you have an NTP server
that is reachable at boot time, and have NTP setup in such a way that
it allows large timesteps on the initial setting of time.

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