Re: Windows timekeeping - NTP

This is a discussion on Re: Windows timekeeping - NTP ; >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 ...

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Thread: Re: Windows timekeeping

  1. Re: Windows timekeeping

    >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).


    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
    reason.

    --
    Bryan Henderson Phone 408-621-2000
    San Jose, California
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  2. Re: Windows timekeeping

    Bryan Henderson wrote:
    >>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).

    >
    >
    > 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.
    >


    The HARDWARE CLOCK knows nothing of time zones; it uses the time it was
    set to whether it was local time, or UTC. The hardware clock is not the
    same as the system clock that Windows uses. The hardware clock is
    battery operated CMOS logic and runs whether the system is powered on or
    not. The system clock is a software/hardware construct with the
    software part belonging to Windows. The hardware part "ticks" and the
    software part counts the ticks. The system clock as I, and others, have
    said keeps UTC unless some idiot has totally botched the configuration
    of Windows (quite possible since the supply of idiots is inexhaustible).

  3. Re: Windows timekeeping

    Bryan Henderson wrote:
    >> 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).

    >
    > 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.


    No, the user sets the initial time when they first build the computer and
    go into the BIOS to set the configuration. Way before any OS is even
    installed. Perhaps these days I should have said "system builder" or
    something like that.

    > 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.


    Windows uses UTC internally and displays whatever the user has requested.
    Other OSes may differ, although I believe that Unix does something
    similar.

    What is different is the OS's assumption about the hardware clock -
    Windows assumes it's local time - the time on the users' wrist watch -
    whereas I believe that Linux assumes differently.

    > 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
    > reason.


    The issue arises, as I understand it, when booting both Windows and Linux
    on the same PC. A related issue can also arise if you have two versions
    of Windows on the same PC, and you boot after an hour change (due to the
    standard/daylight saving transition). When the second OS boots, I may
    also change the hardware clock by one hour (a second time), because it
    also thinks that the clock is in the wrong state. Keeping the hardware
    clock in UTC would avoid this problem, as the OS would never need to
    adjust it. Of course, it would also rely on the user setting the clock in
    UTC correctly in the first place.....

    David



  4. Re: Windows timekeeping

    In article ,
    Richard B. Gilbert wrote:

    > software part counts the ticks. The system clock as I, and others, have
    > said keeps UTC unless some idiot has totally botched the configuration
    > of Windows (quite possible since the supply of idiots is inexhaustible).


    Windows is a brand name that covers two completely different kernels.

    Windows NT based kernels (including Windows 2000, 2003, 2005, and XP) use
    UTC internally. MS-DOS based kernels, including 3.0, 3.1, 95, 98, 98SE and
    ME, use local time. The NT kernels inherit from VMS, not from the
    MS-DOS line.

    I think the history is that MS-DOS was originally an OS for isolated,
    non-portable, machines operated by unsophisticated users, so local time
    was the easiest concept for the users to handle. Unix was developed
    by academics, so they were prepared to deal with more abstract concepts
    and consider the long term.

    Backwards compatibility prevented Microsoft making a change (although
    I seem to remember that Windows can be configured for a UTC RTC, but
    this would probably confuse any new system administrator).

  5. Re: Windows timekeeping

    David Woolley wrote:

    > In article ,
    > Richard B. Gilbert wrote:
    >
    >
    >>software part counts the ticks. The system clock as I, and others, have
    >>said keeps UTC unless some idiot has totally botched the configuration
    >>of Windows (quite possible since the supply of idiots is inexhaustible).

    >
    >
    > Windows is a brand name that covers two completely different kernels.
    >
    > Windows NT based kernels (including Windows 2000, 2003, 2005, and XP) use
    > UTC internally. MS-DOS based kernels, including 3.0, 3.1, 95, 98, 98SE and
    > ME, use local time. The NT kernels inherit from VMS, not from the
    > MS-DOS line.



    I think, that at this point, we can safely ignore any Windows earlier
    than W2k. I'm sure there are a few antiques still running the earlier
    versions but I doubt that there are enough to be significant. It's now
    2006 and the last machines to ship with W98 probably did so in late 1999
    or early 2000. Those machines are now two lifetimes old in computer
    years. W98 is nearly three lifetimes old in computer years.

    W2K and WXP are enough more stable and reliable than W98 that there is
    little reason for anyone but a masochist to still be running W98.
    Damned few people bought ME and even fewer installed it. Microsoft
    pretty much abandoned it years ago. Even W2K is "End of Life";
    Microsoft dropped support a year or two ago.

  6. Re: Windows timekeeping

    In article ,
    Richard B. Gilbert wrote:

    > Most businesses, in the US at least, tend to replace their PCs every
    > three to five years. The replacement is not wholesale, but piecemeal.


    That tends to be true of medium to large private sector businesses.
    Your local plumber will probably wait until the machine dies of old
    age, and it also is less likely to be true of public sector organisations.
    In the UK most of the healthcare industry, for example, is more
    public than private sector. Doctors and dentists also tend to
    fall into the small business category.

    One way or another you have to account for the 70,000,000 Windows 98
    users in June this year.

    > At my last job Windows 95 was the standard desktop in 1998 and Windows
    > 98 was becoming the standard laptop system. When W2K was released,


    Some of the checking I did earlier today indicated that Windows 95
    was still being sold in 1999 (it becan to lose market share in
    2000).

    > really understood Active Directory. I pointed out that we didn't need
    > to use A/D and insisted that the PC people install W2K on my new desktop


    That sounds like an organisation large enough to have an IT department.


  7. Re: Windows timekeeping

    David Woolley wrote:

    > In article ,
    > Richard B. Gilbert wrote:
    >
    >
    >>Most businesses, in the US at least, tend to replace their PCs every
    >>three to five years. The replacement is not wholesale, but piecemeal.

    >
    >
    > That tends to be true of medium to large private sector businesses.


    >>really understood Active Directory. I pointed out that we didn't need
    >>to use A/D and insisted that the PC people install W2K on my new desktop

    >
    >
    > That sounds like an organisation large enough to have an IT department.
    >


    It was. I was a humble laborer in the Network Services Group. We were
    responsible for operating the data center, help desk, purchasing and
    installing PCs, etc. I was a VMS System Administrator, with sidelines
    in Solaris (X86), and Windows. Thanks to the acquisition of the company
    I am now involuntarily retired.

    You don't believe the "humble" part? I confess; I lied!


  8. Re: Windows timekeeping

    Richard B. Gilbert wrote:
    >> That sounds like an organisation large enough to have an IT department.
    >>

    >
    > It was. I was a humble laborer in the Network Services Group. We were
    > responsible for operating the data center, help desk, purchasing and
    > installing PCs, etc. I was a VMS System Administrator, with sidelines
    > in Solaris (X86), and Windows. Thanks to the acquisition of the company
    > I am now involuntarily retired.
    >
    > You don't believe the "humble" part? I confess; I lied!
    >


    No, I don't believe the part about a sideline in Windows...
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  9. Re: Windows timekeeping

    Danny Mayer wrote:

    > Richard B. Gilbert wrote:
    >
    >>>That sounds like an organisation large enough to have an IT department.
    >>>

    >>
    >>It was. I was a humble laborer in the Network Services Group. We were
    >>responsible for operating the data center, help desk, purchasing and
    >>installing PCs, etc. I was a VMS System Administrator, with sidelines
    >>in Solaris (X86), and Windows. Thanks to the acquisition of the company
    >>I am now involuntarily retired.
    >>
    >>You don't believe the "humble" part? I confess; I lied!
    >>

    >
    >
    > No, I don't believe the part about a sideline in Windows...


    As part of our battle with several virii and worms I patched something
    like 100 desktop systems. W2K systems were brought up to SP4 plus all
    available additional patches. WXP systems were brought up to SP1 plus
    all available additional patches. We had a real plague of
    W32.Welchia.*. It was a real nuisance!! Norton usually detected it and
    shut it down before it was fully activated but about one attempt out of
    every thirty was successful. The only way to stamp it out proved to be
    patching the vulnerabilties it used. I also removed viruses and worms
    when found.

    I never touched a Windows or Novell server; I didn't have the training
    and they were too important to have me learn by making mistakes.
    There's still a lot I don't know about Windows. There's still a lot I
    don't know about almost everything. . . .

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