AIX fix for DST changes. - Aix

This is a discussion on AIX fix for DST changes. - Aix ; Folks, I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00), For certain reasons I am not able to update these systems to latest level. When I went to IBM site and tried to download the appropriate ...

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Thread: AIX fix for DST changes.

  1. AIX fix for DST changes.


    Folks,

    I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00),
    For certain reasons I am not able to update these systems to latest
    level. When I went to IBM site and tried to download the appropriate APARS
    the Java applet downloaded lots of other fixes as pre-requisites. These
    fixes would be upgrading lots of files which I am trying to avoid.

    For AIX 4.3.3 IBM suggests that we change TZ variable in /etc/environment
    as follows and re-boot:

    TZ=CST6CDT,M3.2.0,M11.1.0


    Will this work on AIX 5.2 and 5.3 or do I have to update the system?

    Thanks.

    --
    Hemant Shah /"\ ASCII ribbon campaign
    E-mail: NoJunkMailshah@xnet.com \ / ---------------------
    X against HTML mail
    TO REPLY, REMOVE NoJunkMail / \ and postings
    FROM MY E-MAIL ADDRESS.
    -----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
    I haven't lost my mind, Above opinions are mine only.
    it's backed up on tape somewhere. Others can have their own.

  2. Re: AIX fix for DST changes.

    On Feb 15, 3:00 pm, Hemant Shah wrote:
    > Folks,
    >
    > I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00),
    > For certain reasons I am not able to update these systems to latest
    > level. When I went to IBM site and tried to download the appropriate APARS
    > the Java applet downloaded lots of other fixes as pre-requisites. These
    > fixes would be upgrading lots of files which I am trying to avoid.
    >
    > For AIX 4.3.3 IBM suggests that we change TZ variable in /etc/environment
    > as follows and re-boot:
    >
    > TZ=CST6CDT,M3.2.0,M11.1.0
    >
    > Will this work on AIX 5.2 and 5.3 or do I have to update the system?
    >
    > Thanks.
    >
    > --
    > Hemant Shah /"\ ASCII ribbon campaign
    > E-mail: NoJunkMails...@xnet.com \ / ---------------------
    > X against HTML mail
    > TO REPLY, REMOVE NoJunkMail / \ and postings
    > FROM MY E-MAIL ADDRESS.
    > -----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
    > I haven't lost my mind, Above opinions are mine only.
    > it's backed up on tape somewhere. Others can have their own.



    Yes, it works fine. I have tested on AIX 5.1, 5.2 and 5.3
    You need to reboot after settting the TZ variable.




  3. Re: AIX fix for DST changes.

    On Feb 15, 3:00 pm, Hemant Shah wrote:
    > Folks,
    >
    > I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00),
    > For certain reasons I am not able to update these systems to latest
    > level. When I went to IBM site and tried to download the appropriate APARS
    > the Java applet downloaded lots of other fixes as pre-requisites. These
    > fixes would be upgrading lots of files which I am trying to avoid.
    >
    > For AIX 4.3.3 IBM suggests that we change TZ variable in /etc/environment
    > as follows and re-boot:
    >
    > TZ=CST6CDT,M3.2.0,M11.1.0
    >
    > Will this work on AIX 5.2 and 5.3 or do I have to update the system?
    >
    > Thanks.
    >
    > --
    > Hemant Shah /"\ ASCII ribbon campaign
    > E-mail: NoJunkMails...@xnet.com \ / ---------------------
    > X against HTML mail
    > TO REPLY, REMOVE NoJunkMail / \ and postings
    > FROM MY E-MAIL ADDRESS.
    > -----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
    > I haven't lost my mind, Above opinions are mine only.
    > it's backed up on tape somewhere. Others can have their own.


    BTW, the TZ variable does not fix Java
    Some java apps may get their time from the JRE, not the OS




  4. Re: AIX fix for DST changes.

    By not applying the updates, your system will handle all current and
    future dates correctly, but will be using the 2007 DST rules for past
    dates as well. The updates add another entry into a table that allows
    AIX to know when DST changes in any year. Setting the timezone variable
    forces the 2007 rules for all years.

    Excerpt from IBM
    What will happen if I fail to update my system?

    Systems or applications that rely on date or time processing functions could
    make incorrect calculations. Calendar, scheduling, or synchronizing problems
    could arise where systems use date or time stamps, or if dates or times are
    processed or manipulated in any way. In short, if your system makes date or
    time calculations, you may experience calculation errors.
    END excerpt

    The following perl script
    demonstrates this fact.

    #!/usr/bin/perl -w

    if (check_tz(1142592955, 'Fri Mar 17 06:55:55 2006')) {
    print "FWD\n"; # 1142592955 is actually Fri Mar 17 05:55:55 2006
    } elsif (check_tz(1174125355, 'Sat Mar 17 05:55:55 2007')) {
    print "OK\n";
    } else {
    print "BAD\n";
    }


    sub check_tz {
    my ($when, $sb) = @_;

    my $is = scalar localtime($when);
    return ($is eq $sb);
    }


    On Thu, 15 Feb 2007, Hemant Shah wrote:

    >
    > Folks,
    >
    > I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00),
    > For certain reasons I am not able to update these systems to latest
    > level. When I went to IBM site and tried to download the appropriate APARS
    > the Java applet downloaded lots of other fixes as pre-requisites. These
    > fixes would be upgrading lots of files which I am trying to avoid.
    >
    > For AIX 4.3.3 IBM suggests that we change TZ variable in /etc/environment
    > as follows and re-boot:
    >
    > TZ=CST6CDT,M3.2.0,M11.1.0
    >
    >
    > Will this work on AIX 5.2 and 5.3 or do I have to update the system?
    >
    > Thanks.
    >
    > --
    > Hemant Shah /"\ ASCII ribbon campaign
    > E-mail: NoJunkMailshah@xnet.com \ / ---------------------
    > X against HTML mail
    > TO REPLY, REMOVE NoJunkMail / \ and postings
    > FROM MY E-MAIL ADDRESS.
    > -----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
    > I haven't lost my mind, Above opinions are mine only.
    > it's backed up on tape somewhere. Others can have their own.
    >


  5. Re: AIX fix for DST changes.

    While stranded on information super highway aixdude@yahoo.com wrote:
    > On Feb 15, 3:00 pm, Hemant Shah wrote:
    >> Folks,
    >>
    >> I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00),
    >> For certain reasons I am not able to update these systems to latest
    >> level. When I went to IBM site and tried to download the appropriate APARS
    >> the Java applet downloaded lots of other fixes as pre-requisites. These
    >> fixes would be upgrading lots of files which I am trying to avoid.
    >>
    >> For AIX 4.3.3 IBM suggests that we change TZ variable in /etc/environment
    >> as follows and re-boot:
    >>
    >> TZ=CST6CDT,M3.2.0,M11.1.0
    >>
    >> Will this work on AIX 5.2 and 5.3 or do I have to update the system?
    >>
    >> Thanks.
    >>
    >> --
    >> Hemant Shah /"\ ASCII ribbon campaign
    >> E-mail: NoJunkMails...@xnet.com \ / ---------------------
    >> X against HTML mail
    >> TO REPLY, REMOVE NoJunkMail / \ and postings
    >> FROM MY E-MAIL ADDRESS.
    >> -----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
    >> I haven't lost my mind, Above opinions are mine only.
    >> it's backed up on tape somewhere. Others can have their own.

    >
    > BTW, the TZ variable does not fix Java
    > Some java apps may get their time from the JRE, not the OS
    >


    I checked the Java versions, they have the fix for the DST.

    >
    >


    --
    Hemant Shah /"\ ASCII ribbon campaign
    E-mail: NoJunkMailshah@xnet.com \ / ---------------------
    X against HTML mail
    TO REPLY, REMOVE NoJunkMail / \ and postings
    FROM MY E-MAIL ADDRESS.
    -----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
    I haven't lost my mind, Above opinions are mine only.
    it's backed up on tape somewhere. Others can have their own.

  6. Re: AIX fix for DST changes.

    On Thu, 15 Feb 2007 20:00:35 +0000 (UTC), Hemant Shah wrote:

    >
    >Folks,
    >
    > I have couple of system at AIX 5.2 (5200-01) and AIX 5.3 (5300-00),
    > For certain reasons I am not able to update these systems to latest
    > level. When I went to IBM site and tried to download the appropriate APARS
    > the Java applet downloaded lots of other fixes as pre-requisites. These
    > fixes would be upgrading lots of files which I am trying to avoid.
    >
    > For AIX 4.3.3 IBM suggests that we change TZ variable in /etc/environment
    > as follows and re-boot:
    >
    > TZ=CST6CDT,M3.2.0,M11.1.0
    >
    >
    > Will this work on AIX 5.2 and 5.3 or do I have to update the system?
    >
    > Thanks.
    >


    After we updated our AIX 4.3 /etc/environment to
    TZ=EST5EDT,M3.2.0,M11.1.0, we ran tests with scripts both with and
    without TZ=EST5EDT specified first on the ksh command line. The ones
    where TZ was not overriden got correct results because the
    /etc/environment was used. The ones with TZ=EST5EDT got incorrect
    results, as if /etc/environment had not been updated. This was exactly
    as expected, because /etc/environment is only used if TZ is not set in
    the environment. I think IBM's site about DST updates should make a
    point of mentioning this.

    If you only update /etc/environment and your system has scripts that
    set TZ to timezones affected by the update, you may want to change
    those scripts to set the TZ in a way similar to the suggested change
    to /etc/environment.

    I would presume that the same thing happens on AIX 5.2 and 5.3 if you
    only update /etc/environment.

    Bill

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