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Re: hwclock incorrectly set ?

On Sat 10 Mar 2018 at 21:34:24 (-0500), Anil Duggirala wrote:
> On Sat, Mar 10, 2018, at 5:18 PM, Rick Thomas wrote:
> > Hi Charles,
> > 
> > It would be helpful in diagnosing your problem if you could tell us a 
> > little bit more about your configuration…
> > 
> > Questions:
> > 
> > 1) Do you have ntp installed?
> > 
> > 2) Is this a dual-boot system?  (Windows and Debian)
> > 
> > 3) What is the contents of /etc/adjtime?
> > 
> > 
> > Enjoy!
> > Rick
> Dont know if I can intrude like this,


> but I am having getting the same notification at boot time, sometimes. I am on a dual-boot with Win 10. 
> hwclock gives me:
> 2018-03-10 21:19:03.264101-0500
> and date (less than a second later):
> Sat Mar 10 21:19:16 -05 2018
> So this is the opposite time difference than the OP.
> My /etc/adjtime does contain the "LOCAL" flag.
> ntp is not installed in my system and
> timedatectl status outputs:
> Local time: Sat 2018-03-10 21:31:18 -05
>   Universal time: Sun 2018-03-11 02:31:18 UTC
>         RTC time: Sat 2018-03-10 21:31:07
>        Time zone: America/Bogota (-05, -0500)
>  Network time on: yes
> NTP synchronized: no
>  RTC in local TZ: yes
> Warning: The system is configured to read the RTC time in the local time zone.
>          This mode can not be fully supported. It will create various problems
>          with time zone changes and daylight saving time adjustments. The RTC
>          time is never updated, it relies on external facilities to maintain it.
>          If at all possible, use RTC in UTC by calling
>          'timedatectl set-local-rtc 0'.
> I appreciate any help,

My recommendations would be to install ntp on the linux system and let
that take full responsibility for regulating the clock.

I would also set the RTC clock to UTC (either in the CMOS when
next booting, or with hwclock) and tell linux that that is so in
/etc/adjtime. More details in   https://wiki.debian.org/DateTime

Lastly, I would boot up Windows and tell it (a) the RTC is on UTC and
(b) not to make any changes to the time, including daylight savings

(Obviously only one system can be allowed to regulate the clock.)

That's the setup I use on this laptop, and the clock is always
precisely correct with respect to WWVB clock, cell phone, FM radio etc.

However, I have one query (unrelated to Debian) on this subject:

Why is my WWVB clock already showing DST when the clocks don't change
for another three hours? This happens every year, in the early evening
on Saturday. In Britain, clocks running off the "Rugby" time signal
(which now comes from Anthorn in Cumbria) change as they should,
at 01:00 (for spring) on the dot.