system time wrong - Suse

This is a discussion on system time wrong - Suse ; Hi I have a system running community suse 10.2 linux I have configured webmin to update the system time via au.pool.ntp.org , time zone is Melbourne/Australia When I do the date command, the outputted time is 1 hour slow. This ...

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  1. system time wrong

    Hi

    I have a system running community suse 10.2 linux

    I have configured webmin to update the system time via
    au.pool.ntp.org , time zone is Melbourne/Australia

    When I do the date command, the outputted time is 1 hour slow. This
    suggests it is something to do with daylight savings.

    What complicates the issue is that the PHP web applications on the
    server are displaying the correct time! If I manually correct the
    system time, it puts the PHP web applications 1 hour in the future!

    Very confused. any help appreciated

    cheers David

  2. Re: system time wrong

    "linuxnooby@yahoo.com.au" writes:

    >Hi


    >I have a system running community suse 10.2 linux


    >I have configured webmin to update the system time via
    >au.pool.ntp.org , time zone is Melbourne/Australia


    >When I do the date command, the outputted time is 1 hour slow. This
    >suggests it is something to do with daylight savings.


    ntp has absolutely nothing to do with daylight saving. Your system time has
    absolutely nothing to do with daylight saving. Both use UTC which is the
    same all over the world.
    The local time is set by reference to /etc/localtime which should be the
    file /usr/share/zoneinfo/Australia/Melbourne
    And that file should be recent since Australia keeps changing its
    definition of daylight saving time.



    >What complicates the issue is that the PHP web applications on the
    >server are displaying the correct time! If I manually correct the
    >system time, it puts the PHP web applications 1 hour in the future!


    >Very confused. any help appreciated


    >cheers David


  3. Re: system time wrong

    On Thu, 23 Oct 2008, in the Usenet newsgroup alt.os.linux.suse, in article
    <66437708-2c24-4328-a02f-da94f436180c@x16g2000prn.googlegroups.com>,
    linuxnooby@yahoo.com.au wrote:

    NOTE: Posting from groups.google.com (or some web-forums) dramatically
    reduces the chance of your post being seen. Find a real news server.

    >I have a system running community suse 10.2 linux
    >
    >I have configured webmin to update the system time via
    >au.pool.ntp.org , time zone is Melbourne/Australia


    1. NTP is UTC only, and has no concept of timezones, much less daylight
    savings times.
    2. Can't help on webmin - I don't use windoze.

    >When I do the date command, the outputted time is 1 hour slow. This
    >suggests it is something to do with daylight savings.


    What is the difference between 'date -u' and 'date'? The first will
    show UTC, while the second should show what the system libraries think
    is local time. Lessee, Melbourne?

    [compton ~]$ /usr/sbin/zdump -v Australia/Melbourne | grep 2008
    Australia/Melbourne Sat Apr 5 15:59:59 2008 GMT = Sun Apr 6 02:59:59
    2008 EST isdst=1
    Australia/Melbourne Sat Apr 5 16:00:00 2008 GMT = Sun Apr 6 02:00:00
    2008 EST isdst=0
    Australia/Melbourne Sat Oct 4 15:59:59 2008 GMT = Sun Oct 5 01:59:59
    2008 EST isdst=0
    Australia/Melbourne Sat Oct 4 16:00:00 2008 GMT = Sun Oct 5 03:00:00
    2008 EST isdst=1
    [compton ~]$ /usr/sbin/zdump Australia/Melbourne ; date -u
    Australia/Melbourne Sat Oct 25 06:49:44 2008 EST
    Fri Oct 24 19:49:44 UTC 2008
    [compton ~]$

    Looks like 11 hours. (I have to use 'zdump' here, because I'm a quarter
    of the way around the world from Melbourne and am not in the same
    timezone ;-)

    >What complicates the issue is that the PHP web applications on the
    >server are displaying the correct time! If I manually correct the
    >system time, it puts the PHP web applications 1 hour in the future!


    Is that the same system? Or are you seeing some strange crap because
    of UTC timestamps used in *nix.

    You might want to check to see what time zone file package you have.
    The command is probably 'rpm -q tzdata'. Oz changed the effective
    dates for start/end of daylight savings time from 'last Sunday in
    October and March' to 'first Sunday in October and April' back in
    July of last year, so your tzdata file has to be based on tzdata2007g
    that was released on Aug 20, 2007, OR LATER (though there were no
    changes to the Australian zonefiles since that date). The latest
    tzdata source file (on ftp://elsie.nci.nih.gov/pub - which may not
    be available through your errata program yet) is tzdata2008h.tar.gz
    dated 11 days ago (it only effected Mauritius and Syria).

    Old guy

  4. Re: system time wrong

    linuxnooby@yahoo.com.au wrote:
    > I have a system running community suse 10.2 linux
    >
    > I have configured webmin to update the system time via
    > au.pool.ntp.org , time zone is Melbourne/Australia
    >
    > When I do the date command, the outputted time is 1 hour slow. This
    > suggests it is something to do with daylight savings.


    As much as there is wrong with daylight savings in itself, I doubt that
    is the problem.

    > What complicates the issue is that the PHP web applications on the
    > server are displaying the correct time! If I manually correct the
    > system time, it puts the PHP web applications 1 hour in the future!
    >
    > Very confused. any help appreciated


    What time is the bios? A simple `date` should show you the correct time.
    Unless you have a dual boot, the time must be UTC. In YaST, System. Date
    and Time, you must also select 'Hardware Clock Set To UTC'. Also select
    the coorect timezone there.

    Once you have gotten that, all should be well. If php then still shows
    the wrong time, the problem is php related and should be solved there.

    Obviously see that you have done an update. I know that in the past just
    after some version came out, dates for daylight changed and without it,
    you would get a difference during at least 2 or 3 weeks.

    houghi
    --
    Theologians can pursuade themselves of anything. Anyone who can worship
    a trinity and insists that his religion is a monotheism can believe
    anything -- just give him time to rationalize it.
    Robert A. Heinlein, JOB: A Comedy of Justice

  5. Re: system time wrong



    linuxnooby@yahoo.com.au wrote:
    > Hi
    >
    > I have a system running community suse 10.2 linux
    >
    > I have configured webmin to update the system time via
    > au.pool.ntp.org , time zone is Melbourne/Australia
    >
    > When I do the date command, the outputted time is 1 hour slow. This
    > suggests it is something to do with daylight savings.
    >
    > What complicates the issue is that the PHP web applications on the
    > server are displaying the correct time! If I manually correct the
    > system time, it puts the PHP web applications 1 hour in the future!
    >
    > Very confused. any help appreciated
    >
    > cheers David


    Is your computer about 5 years old? Might be time to change the battery
    on the motherboard.
    You didn't give much detail of your situation so I'm guessing.

    Regards,
    Werner

  6. Re: system time wrong

    On Sun, 26 Oct 2008, in the Usenet newsgroup alt.os.linux.suse, in article
    , Werner wrote:

    >linuxnooby@yahoo.com.au wrote:


    >> I have a system running community suse 10.2 linux


    and how old is that?

    >> I have configured webmin to update the system time via
    >> au.pool.ntp.org , time zone is Melbourne/Australia


    Australia changed the effective dates for start/end of daylight savings
    time from 'last Sunday in October and March' to 'first Sunday in
    October and April' back in July of last year. NTP can be set up
    to initially set the system time (though this is not the default
    behavior, and OTHERWISE, NTP will not correct a time error in excess
    of about 15 minutes) - but the NTP protocol only knows UTC and you then
    depend on the timezone files to determine the correct wall-clock time.

    >> When I do the date command, the outputted time is 1 hour slow. This
    >> suggests it is something to do with daylight savings.
    >>
    >> What complicates the issue is that the PHP web applications on the
    >> server are displaying the correct time! If I manually correct the
    >> system time, it puts the PHP web applications 1 hour in the future!


    >Is your computer about 5 years old? Might be time to change the battery
    >on the motherboard.


    CMOS batteries don't put _some_ times off by an hour, and some not.

    The CMOS battary powers the hardware clock when the computer is off.
    When the system is on, power for the hardware clock is often derived
    from the +5 logic. Additionally, the hardware clock is only used
    to initially set the system clock. The system clock in an Intel type
    of system (includes AMD, Cyrix, and similar) is a software counter in
    the kernel that counts hardware interrupts. You can see this by finding
    a command line, and issuing the command 'cat /proc/interrupts' ten
    seconds apart. Look at the difference in the counts for IRQ 0.
    Depending on how your kernel was compiled, there may be 100, 200, 500,
    or 1000 interrupts _per_second_ recorded for that IRQ.

    Old guy

  7. Re: system time wrong

    Thanks for all the replies.

    Turned out the timezone package needed to be updated, time would have
    been displaying incorrectly for 3 weeks

    When I looked at the server today the system time was displaying
    correctly for daylight savings. (Today is after last weekend in
    october, last week was not).

    In any case I installed latest timezone package , timezone
    2.5-34.13.rpm

    Again thanks for the replies. I have learnt something

    cheers David


    > You might want to check to see what time zone file package you have.
    > The command is probably 'rpm -q tzdata'. *Oz changed the effective
    > dates for start/end of daylight savings time from 'last Sunday in
    > October and March' to 'first Sunday in October and April' back in
    > July of last year, so your tzdata file has to be based on tzdata2007g
    > that was released on Aug 20, 2007, *OR LATER (though there were no
    > changes to the Australian zonefiles since that date). The latest
    > tzdata source file (onftp://elsie.nci.nih.gov/pub- which may not
    > be available through your errata program yet) is tzdata2008h.tar.gz
    > dated 11 days ago (it only effected Mauritius and Syria).
    >
    > * * * * Old guy



  8. Re: system time wrong


    inuxnooby@yahoo.com.au wrote:
    > Thanks for all the replies.
    >
    > Turned out the timezone package needed to be updated, time would have
    > been displaying incorrectly for 3 weeks


    1) Please do not toppost
    2) Told you so

    houghi
    --
    But I will accept the rules that you feel necessary to your freedom. I am
    free, no matter what rules surround me. If I find them tolerable, I
    tolerate them; if I find them too obnoxious, I break them. I am free
    because I know that I alone am morally responsible for everything I do.

  9. Re: system time wrong

    houghi writes:


    >inuxnooby@yahoo.com.au wrote:
    >> Thanks for all the replies.
    >>
    >> Turned out the timezone package needed to be updated, time would have
    >> been displaying incorrectly for 3 weeks


    >1) Please do not toppost


    Why not? Why do you believe that imposing your bizare notions onto the
    world is an appropriate thing to do.

    >2) Told you so


    Why does anyone care that you told him so? Many people did AND told him how
    to fix it. People come here with problems that we help them fix. This is
    NOT a blame game. I think you must have gotten out of bed on the wrong side
    this morning.


    >houghi
    >--
    >But I will accept the rules that you feel necessary to your freedom. I am
    >free, no matter what rules surround me. If I find them tolerable, I
    >tolerate them; if I find them too obnoxious, I break them. I am free
    >because I know that I alone am morally responsible for everything I do.


  10. Re: system time wrong


    It seems this problem could have been solved much more easily. I
    accepted a kernel update yesterday but after installing it my system
    time went wrong, staying behind by about 26 minutes. I fixed it using
    YaST by following the instructions from http://en.opensuse.org/SDB:Changing_..._-_SDB_Example


  11. Re: system time wrong

    On Tue, 28 Oct 2008, in the Usenet newsgroup alt.os.linux.suse, in article
    <464cbfaa-7e1c-4ccd-93f2-bf819857313d@l77g2000hse.googlegroups.com>, kiwanuka
    wrote:

    NOTE: Posting from groups.google.com (or some web-forums) dramatically
    reduces the chance of your post being seen. Find a real news server.

    >


    Yes, snipping is good, but it would have helped to have some clue
    about what you are referring to.

    >It seems this problem could have been solved much more easily. I
    >accepted a kernel update yesterday but after installing it my system
    >time went wrong, staying behind by about 26 minutes.


    No, you are discussing a completely different problem - your clock
    got mis-set somehow (probably because your CMOS or hardware clock was
    incorrect by 26 minutes). In the O/P's case, the _timezone_ information
    was outdated. If you look at the 398 timezones used around the world
    there are 39 clock offsets (41 if you include daylight saving time)
    currently in use:

    [compton ~]$ cut -f5 time.2008h/Time.zone.names | sort -un | column
    -11:00 -8:00 -4:00 -2:00 2:00 4:30 6:00 8:45 10:30 12:45
    -10:00 -7:00 -4:30 -1:00 3:00 5:00 6:30 9:00 11:00 13:00
    -9:00 -6:00 -3:00 0:00 3:30 5:30 7:00 9:30 11:30 14:00
    -9:30 -5:00 -3:30 1:00 4:00 5:45 8:00 10:00 12:00
    [compton ~]$

    Google says you are posting from Oxford, and your times should have
    reset from BST to GMT very early Sunday morning. Thus, if you can find
    a command line, 'date -u ; date' should return the same times, and
    'date ; /sbin/hwclock -r' should report _similar_ times to within a few
    seconds (because your CMOS clock being on localtime or UTC should still
    be the same as your current time).

    >I fixed it using YaST by following the instructions from
    > http://en.opensuse.org/SDB:Changing_..._-_SDB_Example


    And you missed the O/P's statement that he was using NTP, which only
    knows UTC, and has no information about timezones or daylight saving
    times. Your timezone configuration has to be correct.

    Old guy

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