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List:       aix-l
Subject:    Re: Time Puzzle (and DST update about the web link)
From:       "Davignon, Edward" <Edward.Davignon () ENERGYEAST ! COM>
Date:       2007-02-04 23:21:59
Message-ID: 873F7EFCE3CA454AA6D3AC34FAEA5130A69A91 () ROCMSGCL02 ! Energyeast ! net
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Karl,
On second observation, it looks like some of the times are reported in
UTC (or "GMT" time) and some are reported in CST.  Your TZ variable
would be set to CST6CDT.  The 6 is the number of hours that CST time is
offset from UTC time.  This is why in one place it is reported at 21:32
and the other place it is reported as 15:32 CST.  Try typing the
command:
TZ= date
Or 
TZ=UTC date

BTW, many system log files are logged in UTC time.  Also, watch out for
this when reading logs generated by syslog.  Syslog does NOT convert the
time to a standard time zone such as UTC or the value of TZ in the
syslogd process, so client programs are free to report in whatever time
zone they desire.  This is why syslog logs are in first-in-first-out
order, but the time stamps frequently switch between local time and UTC
time.

Sorry about my first answer, I should have read your question a little
more carefully.

Edward Davignon
Lead Analyst - Distributed Systems
Utility Shared Services - IT
Energy East Corporation


-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@Princeton.EDU] On Behalf Of
Karl
Sent: Sunday, February 04, 2007 12:21 AM
To: aix-l@Princeton.EDU
Subject: Re: Time Puzzle (and DST update about the web link)

No we do not use NTP.  Just to stress, I am not concerned 
about the time being off on our system.  It seems accurate 
to me.  Further, we have made no significant changes to 
our system in months. 

What is puzzling to me is how I can have a record of 
myself signing in from a machine whose time I am also 
confident of and have a time discrepancy of multiple hours 
when both are in the same time zone and set as such.

==============================================

Karl,
Are you running Network Time Protocol (NTP)?  Did you have 
a
misconfigured NTP server in your NTP configuration?

Without Network Time Protocol (or another clock discipline 
method), most
clocks will use the AC cycle (60 HZ in the USA) as their 
reference
frequency and will drift wildly depending on the quality 
of the power.
Power conditioning will help, but NTP should keep the 
clocks in sync
with each other.  There are NTP hardware devices 
(appliances) that
receive radio signals that are broadcast by governments 
that keep your
clocks in sync with a national standard clock.  

Also, if you lose power and switch to a local generator, 
the quality of
the power from a local generator tends to vary frequency 
by the load of
the generator, this will drive the clocks crazy too.  I 
found this out
when I ran my alarm clock off a generator that was running 
at 62 HZ.  By
morning, my alarm clock was significantly ahead of my 
battery-powered
clocks!


Edward Davignon
Lead Analyst - Distributed Systems
Utility Shared Services - IT
Energy East Corporation

-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@Princeton.EDU] 
On Behalf Of
Karl Jones
Sent: Friday, February 02, 2007 10:03 AM
To: aix-l@Princeton.EDU
Subject: Re: Time Puzzle (and DST update about the web 
link)

I have not been experimenting with TZ.  Further, in one 
instance, the 
user is me from a machine which I know is set for the same 
time zone.  
Nevertheless it is the only lead I have so far so I will 
look into it.

Andrew.Townsend@BISYS.COM wrote:
> > Let me guess, you're experimenting with the TZ ?
> >
> > I am testing the chtz command and I have seen that same thing as
well.
> >
> > By the way, if you are looking at this website that shows you how to
change
> > the timzone information to reflect the upcoming changes in Daylight
Savings
> > Time (only for those of use that aren't at the supported level):
> >
> > http://www-1.ibm.com/support/docview.wss?rs=0&uid=isg3T1000252
> >
> > The command on the website shows this command (For EST):
> >
> > chtz TZ=EST5EDT,M3.2.0/2:00:00,M11.1.0/2:00:00
> >
> > The command should be:
> >
> > chtz EST5EDT,M3.2.0/2:00:00,M11.1.0/2:00:00
> >
> > I called IBM and told them so hopefully it will be changed on the
website
> > soon.
> >
> > Once the command is run, check the /etc/environment and look at the
TZ=
> > line. If you use the command shown on the website you will see:
> >
> > TZ=TZ=EST5EDT,M3.2.0/2:00:00,M11.1.0/2:00:00
> >
> > what you want to see is:
> >
> > TZ=EST5EDT,M3.2.0/2:00:00,M11.1.0/2:00:00
> >
> > Drew
> >
> >
> >
> >

> >              Karl Jones

> >              <kjones@stpaullin

> >              ocpt.com>
To 
> >              Sent by: IBM AIX          aix-l@Princeton.EDU

> >              Discussion List
cc 
> >              <aix-l@Princeton.

> >              EDU>
Subject 
> >                                        Time Puzzle

> >

> >              02/01/2007 04:47

> >              PM

> >

> >

> >              Please respond to

> >              kjones@stpaullino

> >                   cpt.com

> >

> >

> >
> >
> >
> >
> > I am puzzled by the date stamps here.  How is this possible?
> >
> > Last unsuccessful login: Thu Feb  1 20:58:34 2007 on ssh from
> > 221.208.160.11
> > Last login: Thu Feb  1 21:32:06 2007 on ssh from karl-jones
> > [snip]
> > F50:/ # date
> > Thu Feb  1 15:32:40 CST 2007
> >
> >   
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