How to coordinate the clock when dual-booting with Windows

Kevin O'Gorman kogorman at gmail.com
Tue Dec 12 04:35:56 UTC 2017


On Mon, Dec 11, 2017 at 6:41 PM, J. L. <jl.ffm at gmx.net> wrote:

> On 11.12.2017 22:07, Drew Einhorn wrote:
> > NTP is probably assuming system clock is UTC and correcting based on
> > your time zone settings. This way ntp can assume all clocks are UTC and
> > not have figure out all the relevant time zone corrections.
> >
> > Does this make sense for your time zone?
> >
> > Remote users can set their time zone environment variables for their
> > local time zone. Things work out nicely on Unix or Linux based systems.
> >
> > I don't know If there is a right way to configure Windows so it knows
> > the hardware clock is UTC and the user time zone is different. If not,
> > you have different issues depending on whether the hardware clock is UTC
> > or local time. You may have to decide which issues are the bigger
> problem.
> >
> > Windows may screw things up for spring and fall daylight savings
> > adjustments, if Windows thinks the hardware is on local time when it's
> > really on UTC.
> >
> > If the latest updates are not installed, your systems may change to or
> > from daylight savings on the wrong weekend. This can be an issue for all
> > operating systems.
> >
> > My daughter's alarm clock switched itself from daylight savings time to
> > standard time on the wrong weekend this year. And, there is no way to
> > update the rules for when to change.
> >
> >
> >
> > On December 11, 2017, at 12:47 PM, Kevin O'Gorman <kogorman at gmail.com>
> > wrote:
> >
> >
> > On Sun, Dec 10, 2017 at 11:23 PM, Grizzly via ubuntu-users
> > <ubuntu-users at lists.ubuntu.com <mailto:ubuntu-users at lists.ubuntu.com>>
> > wrote:
> >
> >     10 December 2017  at 20:41, Kevin O'Gorman wrote:
> >     Re: How to coordinate the clock whe (at least in part)
> >
> >     >On Sun, Dec 10, 2017 at 12:59 PM, Grizzly via ubuntu-users <
> >     >ubuntu-users at lists.ubuntu.com
> >     <mailto:ubuntu-users at lists.ubuntu.com>> wrote:
> >     >
> >     >> 10 December 2017  at 15:52, Colin Law wrote:
> >     >> Re: How to coordinate the clock whe (at least in part)
> >     >>
> >     >> >On 10 December 2017 at 15:45, Liam Proven <lproven at gmail.com
> <mailto:lproven at gmail.com>> wrote:
> >     >> >
> >     >> >> On 10 December 2017 at 10:42, Colin Law <clanlaw at gmail.com
> <mailto:clanlaw at gmail.com>> wrote:
> >     >> >> >
> >     >> >> > The clock is not normally an issue when dual booting.
> >     >> >>
> >     >> >> It bally well is for me!
> >     >> >>
> >     >> >> E.g. if it's set to local time, both OSes move the system clock
> >     >> >> forward or backwards when daylight savings times begins or
> ends,
> >     >> >> resulting in a 2h discrepancy.
> >     >> >>
> >     >> >> My solution: minimize use of Windows. I boot it a couple of
> times a
> >     >> >> year, if that, normally.
> >     >> >>
> >     >> >
> >     >> >Interesting, I have never seen that. I assumed the system clock
> was in
> >     >> UTC,
> >     >> >and so would not change with DST.  You may be right about that
> though, I
> >     >> >have no evidence either way. However I would have thought it
> would re-sync
> >     >> >the next time ntpdate or whatever it is that does the auto
> timesync ran.
> >
> >     >> Its on a tab in date/time that not many people visit, default is
> off
> >
> >     >> That's what I was hoping, but I cannot find anything about NTP in
> my
> >     >Windows 10.
> >
> >     Must admit I was unsure if the same controls carry forward to later
> >     windoz, (I
> >     stopped at Win7) it looks like they do
> >
> >     https://www.isunshare.com/windows-10/2-ways-to-change-
> date-and-time-on-windows-1
> >     0.html
> >     <https://www.isunshare.com/windows-10/2-ways-to-change-
> date-and-time-on-windows-1%0A0.html>
> >
> >     only difference appears that you only see the internet time when you
> >     click
> >     "Change date time"
> >
> >     here it (now) has a number of possible time server, IIRC it came
> >     with only two
> >     (unreliable), the rest I added later
> >
> >     there is a reg entry
> >
> >     [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
> CurrentVersion\DateTime\Servers]
> >     @="3"
> >     "1"="time.windows.com <http://time.windows.com>"
> >     "2"="129.6.15.29 <http://129.6.15.29>"
> >     "3"="0.uk.pool.ntp.org <http://0.uk.pool.ntp.org>"
> >     "4"="1.uk.pool.ntp.org <http://1.uk.pool.ntp.org>"
> >     "6"="ntp2b.mcc.ac.uk <http://ntp2b.mcc.ac.uk>"
> >     "5"="ntp2a.mcc.ac.uk <http://ntp2a.mcc.ac.uk>"
> >     "7"="ntp2c.mcc.ac.uk <http://ntp2c.mcc.ac.uk>"
> >     "8"="ntp2d.mcc.ac.uk <http://ntp2d.mcc.ac.uk>"
> >     "9"="ntp.exnet.com <http://ntp.exnet.com>"
> >
> >     the chosen NTP server does propagate to other Reg entries
> >
> >     but you can manually add direct in the dialogue if you don't want to
> >     delve in
> >     Registry
> >
> >
> > This is interesting, but I'm uncertain how to use it.  I found the list
> > of servers in the registry.  I didn't put them there, but there are 5,
> > and number 5 appears as the default.  It is time-b.nist.gov
> > <http://time-b.nist.gov> which I sure hope is not unreliable.  However,
> > I still get Windows showing the time off by 8 hours when it boots up,
> > and I'm supposing that's because it is using the time in the BIOS DRAM,
> > but I'm unsure because as near as I can tell the BIOS is set to local
> > time; at least that's what I see when I'm in BIOS setup.  Frankly I'm
> > all confused.
> >
> > It would be nice if Windows would use nist.gov <http://nist.gov> and
> > apply the timezone, ignoring BIOS completely.
> >
> > --
> > Kevin O'Gorman
> > #define QUESTION ((bb) || (!bb))   /* Shakespeare */
> >
> >       Please consider the environment before printing this email.
>
>
> Hi!
>
> Could it be that You did not even think of trying to use a search engine
> for your problem?
>
> So, i'm a nice guy and did just one little search [coordinate time dual
> boot system windows linux] and will paste You _some_ not even all of the
> links i found obviously quite fitting to Your question:
>
> http://ubuntuhandbook.org/index.php/2016/05/time-differences-ubuntu-1604-
> windows-10/
>
> https://askubuntu.com/questions/800914/clock-shows-
> wrong-time-after-switching-from-ubuntu-to-windows-10
>
> https://askubuntu.com/questions/169376/clock-time-is-off-on-dual-boot
>
> http://www.webupd8.org/2014/09/dual-boot-fix-time-differences-between.html
>
> https://www.ghacks.net/2017/07/30/fixing-incorrect-clock-
> time-settings-while-dual-booting-windowslinux/
>
> https://lifehacker.com/5742148/fix-windows-clock-
> issues-when-dual-booting-with-os-x
>
> https://www.howtogeek.com/211144/how-to-get-windows-and-
> linux-clocks-to-display-the-correct-and-matching-time-dual-boot/
>
> https://www.youtube.com/watch?v=Gqre5fRo704
>
> https://techlr.de/dual-boot-windows-10-und-linux-falsche-uhrzeit/
>
>
> I'm pretty sure the information You asked for is hidden somewhere in
> these links ...! ;-)
>
> Hope i did You a little favor!
>
> Good luck!
>
> J. L.
>
> Not as much of a favor, as we'd both like.

Ignoring the snarkiness of the tone, yours is of course a reasonable
suggestion.  But may I emphasize your own use of the word "hidden".  And
the fact that I or even "we" may have already done that and wound up with a
different experience than the articles claim.

Of course, if you had read and understood our conversation you would have
noticed that.

Just taking the first article.  I tried it's use of timedatectl.  It didn't
help, even though the properties match those reported in the article.

And so on, perhaps.  I choose not to wade through a bunch of unverified
suggestions and to hope that cooperating individuals can bring out each
others' best thinking and arrive at a solution.
And perhaps even a better understanding of the underlying techology.
Sometimes it even works.  Not in this case, at least so far.

I may get desperate and look further into your list.  Anyway, thanks for
trying.

-- 
Kevin O'Gorman
#define QUESTION ((bb) || (!bb))   /* Shakespeare */

Please consider the environment before printing this email.
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