* Need to set TIMEZONE in Linux
@ 2003-06-03 8:44 Sarika Inamdar
2003-06-03 8:49 ` oford
2003-06-03 8:52 ` Horia Chirculescu
0 siblings, 2 replies; 6+ messages in thread
From: Sarika Inamdar @ 2003-06-03 8:44 UTC (permalink / raw)
To: linux-admin
Hi All,
We need to set the timezone for Linux. Its showing EDT as the time zone.
We need to set it to PST/GMT.
How do I do this ?
There is a file under /usr/share/zoneinfo/zone.tab . What does this do ?
We have a requirement, where a user during installation of appliaction
on Luinux, should be prompted for timezone change. What file needs to be
updated and which command should be used to set the timezone.
Thanks in Advance for the help,
Sarika
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Need to set TIMEZONE in Linux
2003-06-03 8:44 Need to set TIMEZONE in Linux Sarika Inamdar
@ 2003-06-03 8:49 ` oford
2003-06-03 8:52 ` Horia Chirculescu
1 sibling, 0 replies; 6+ messages in thread
From: oford @ 2003-06-03 8:49 UTC (permalink / raw)
To: sinamdar; +Cc: linux-admin
[-- Attachment #1: Type: text/plain, Size: 877 bytes --]
On Tue, 2003-06-03 at 03:44, Sarika Inamdar wrote:
> Hi All,
>
> We need to set the timezone for Linux. Its showing EDT as the time zone.
> We need to set it to PST/GMT.
> How do I do this ?
>
> There is a file under /usr/share/zoneinfo/zone.tab . What does this do ?
>
> We have a requirement, where a user during installation of appliaction
> on Luinux, should be prompted for timezone change. What file needs to be
> updated and which command should be used to set the timezone.
>
> Thanks in Advance for the help,
> Sarika
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Should be /etc/localtime. Mine is a symlink to the /usr/share/zoneinfo/CST6CDT file.
--
Owen Ford <oford@ev1.net>
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Need to set TIMEZONE in Linux
2003-06-03 8:44 Need to set TIMEZONE in Linux Sarika Inamdar
2003-06-03 8:49 ` oford
@ 2003-06-03 8:52 ` Horia Chirculescu
2003-06-03 9:52 ` Sarika Inamdar
1 sibling, 1 reply; 6+ messages in thread
From: Horia Chirculescu @ 2003-06-03 8:52 UTC (permalink / raw)
To: Sarika Inamdar; +Cc: linux-admin
[-- Attachment #1: Type: TEXT/PLAIN, Size: 1559 bytes --]
See the attached html file. It is a small document that covers the issue.
Have a nice day.
____ ____ o ~
// // / __ \ // \ // //'''' //\\
//_____// / / / / //___ / // // // \\
// // / /_/ / // \ // // //____\\
// // \____/ // \ // \\.... // \\
------------------------------------------------------------------------
Comtec Net Romania
----------------------------------------------------
WEB: www.eltop.ro IRC: irc.eltop.ro NEWS: news.eltop.ro
----------------------------------------------------
Horia Chirculescu root@eltop.ro
Connex: +40 723 205 086
Zapp: +40 788 374 059
On Tue, 3 Jun 2003, Sarika Inamdar wrote:
> Hi All,
>
> We need to set the timezone for Linux. Its showing EDT as the time zone.
> We need to set it to PST/GMT.
> How do I do this ?
>
> There is a file under /usr/share/zoneinfo/zone.tab . What does this do ?
>
> We have a requirement, where a user during installation of appliaction
> on Luinux, should be prompted for timezone change. What file needs to be
> updated and which command should be used to set the timezone.
>
> Thanks in Advance for the help,
> Sarika
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
[-- Attachment #2: Type: TEXT/PLAIN, Size: 8001 bytes --]
<HTML>
<HEAD>
<TITLE>Linux Tips - Linux, Clocks, and Time</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF">
<P><IMG ALT="LinuxSA" SRC="/images/linuxsabar.jpg" WIDTH="431" HEIGHT="50"></P>
<H1>Linux Tips<BR>
Linux, Clocks, and Time</H1>
<P ALIGN=CENTER>
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<HR WIDTH="50%">
<H2>Introduction</H2>
<P>This document explains how to set your computer's clock from Linux,
how to set your timezone, and other stuff related to Linux and how it
does its time-keeping.</P>
<P>Your computer has two timepieces; a battery-backed one that is
always running (the ``hardware'', ``BIOS'', or ``CMOS'' clock), and
another that is maintained by the operating system currently running
on your computer (the ``system'' clock). The hardware clock is
generally only used to set the system clock when your operating system
boots, and then from that point until you reboot or turn off your
system, the system clock is the one used to keep track of time.</P>
<P>On Linux systems, you have a choice of keeping the hardware clock
in UTC/GMT time or local time. The preferred option is to keep it in
UTC because then daylight savings can be automatically accounted for.
The only disadvantage with keeping the hardware clock in UTC is that
if you dual boot with an operating system (such as DOS) that expects
the hardware clock to be set to local time, the time will always be
wrong in that operating system.</P>
<H2>Setting your timezone</H2>
<P>The timezone under Linux is set by a symbolic link from
<CODE>/etc/localtime</CODE><SUP><A HREF="#note1">[1]</A></SUP> to a
file in the <CODE>/usr/share/zoneinfo</CODE><SUP><A
HREF="#note2">[2]</A></SUP> directory that corresponds with what
timezone you are in. For example, since I'm in South Australia,
<CODE>/etc/localtime</CODE> is a symlink to
<CODE>/usr/share/zoneinfo/Australia/South</CODE>. To set this link,
type:</P>
<P><CODE>ln -sf ../usr/share/zoneinfo/<I>your/zone</I> /etc/localtime</CODE></P>
<P>Replace <CODE><I>your/zone</I></CODE> with something like
<CODE>Australia/NSW</CODE> or <CODE>Australia/Perth</CODE>. Have a
look in the directories under <CODE>/usr/share/zoneinfo</CODE> to see
what timezones are available.</P>
<P><FONT SIZE="-1"><A NAME="note1">[1]</A> This assumes that
<CODE>/usr/share/zoneinfo</CODE> is linked to
<CODE>/etc/localtime</CODE> as it is under Red Hat Linux.</FONT></P>
<P><FONT SIZE="-1"><A NAME="note2">[2]</A> On older systems, you'll
find that <CODE>/usr/lib/zoneinfo</CODE> is used instead of
<CODE>/usr/share/zoneinfo</CODE>. See also the later section ``<A
HREF="#wrongtime">The time in some applications is wrong</A>''.</FONT></P>
<H2>Setting UTC or local time</H2>
<P>When Linux boots, one of the initialisation scripts will run the
<CODE>/sbin/hwclock</CODE> program to copy the current hardware clock
time to the system clock. <CODE>hwclock</CODE> will assume the
hardware clock is set to local time unless it is run with the
<CODE>--utc</CODE> switch. Rather than editing the startup script,
under Red Hat Linux you should edit the
<CODE>/etc/sysconfig/clock</CODE> file and change the
``<CODE>UTC</CODE>'' line to either ``UTC=true'' or ``UTC=false'' as
appropriate.</P>
<H2>Setting the system clock</H2>
<P>To set the system clock under Linux, use the <CODE>date</CODE>
command. As an example, to set the current time and date to July 31,
11:16pm, type ``<CODE>date 07312316</CODE>'' (note that the time is
given in 24 hour notation). If you wanted to change the year as well,
you could type ``<CODE>date 073123161998</CODE>''. To set the seconds
as well, type ``<CODE>date 07312316.30</CODE>'' or ``<CODE>date
073123161998.30</CODE>''. To see what Linux thinks the current local
time is, run <CODE>date</CODE> with no arguments.</P>
<H2>Setting the hardware clock</H2>
<P>To set the hardware clock, my favourite way is to set the system
clock first, and then set the hardware clock to the current system
clock by typing ``<CODE>/sbin/hwclock --systohc</CODE>'' (or
``<CODE>/sbin/hwclock --systohc --utc</CODE>'' if you are keeping the
hardware clock in UTC). To see what the hardware clock is currently
set to, run <CODE>hwclock</CODE> with no arguments. If the hardware
clock is in UTC and you want to see the local equivalent, type
``<CODE>/sbin/hwclock --utc</CODE>''</P>
<H2><A NAME="wrongtime">The time in some applications is
wrong</A></H2>
<P>If some applications (such as <CODE>date</CODE>) display the
correct time, but others don't, and you are running Red Hat Linux 5.0
or 5.1, you most likely have run into a bug caused by a move of the
timezone information from <CODE>/usr/lib/zoneinfo</CODE> to
<CODE>/usr/share/zoneinfo</CODE>. The fix is to create a symbolic
link from <CODE>/usr/lib/zoneinfo</CODE> to
<CODE>/usr/share/zoneinfo</CODE>: ``<CODE>ln -s ../share/zoneinfo
/usr/lib/zoneinfo</CODE>''.</P>
<H2>Summary</H2>
<UL>
<LI><CODE>/etc/sysconfig/clock</CODE> sets whether the hardware clock
is stored as UTC or local time.<P>
<LI>Symlink <CODE>/etc/localtime</CODE> to
<CODE>/usr/share/zoneinfo/...</CODE> to set your timezone.<P>
<LI>Run ``<CODE>date MMDDhhmm</CODE>'' to set the current system
date/time.<P>
<LI>Type ``<CODE>/sbin/hwclock --systohc [--utc]</CODE>'' to set the
hardware clock.<P>
</UL>
<H2>Other interesting notes</H2>
<P>The Linux kernel always stores and calculates time as the number of
seconds since midnight of the 1st of January 1970 UTC regardless of
whether your hardware clock is stored as UTC or not. Conversions to
your local time are done at run-time. One neat thing about this is
that if someone is using your computer from a different timezone, they
can set the TZ environment variable and all dates and times will
appear correct for their timezone.</P>
<P>If the number of seconds since the 1st of January 1970 UTC is
stored as an signed 32-bit integer (as it is on your Linux/Intel
system), your clock will stop working sometime on the year 2038.
Linux has no inherent Y2K problem, but it does have a year 2038
problem. Hopefully we'll all be running Linux on 64-bit systems by
then. 64-bit integers will keep our clocks running quite well until
aproximately the year 292271-million.</P>
<H2>Other programs worth looking at</H2>
<UL>
<LI><CODE>rdate</CODE> - get the current time from a remote machine;
can be used to set the system time.<P>
<LI><CODE>xntpd</CODE> - like <CODE>rdate</CODE>, but it's extremely
accurate and you need a permanent 'net connection. <CODE>xntpd</CODE>
runs continuously and accounts for things like network delay and clock
drift, but there's also a program (<CODE>ntpdate</CODE>) included that
just sets the current time like rdate does.<P>
</UL>
<H2>Further information</H2>
<UL>
<LI><CODE>date(1)</CODE><P>
<LI><CODE>hwclock(8)</CODE><P>
<LI><CODE>/usr/doc/HOWTO/mini/Clock</CODE><P>
</UL>
<HR WIDTH="50%">
<DIV ALIGN=CENTER>
<ADDRESS><FONT SIZE=-1>
Web page suggestions, criticisms, general info, or submissions to<br>
the <A HREF="/people/">LinuxSA Webmaster</A>
(<A HREF="mailto:webmaster@linuxsa.org.au">webmaster@linuxsa.org.au</A>)
</FONT></ADDRESS>
</DIV>
<P ALIGN=CENTER>
<FONT SIZE=-1><EM>Last updated: Thursday, 06-Aug-1998 02:46:26 CST</EM></FONT>
</P>
</BODY>
</HTML>
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Need to set TIMEZONE in Linux
2003-06-03 8:52 ` Horia Chirculescu
@ 2003-06-03 9:52 ` Sarika Inamdar
2003-06-03 9:55 ` oford
0 siblings, 1 reply; 6+ messages in thread
From: Sarika Inamdar @ 2003-06-03 9:52 UTC (permalink / raw)
To: 'Horia Chirculescu'; +Cc: linux-admin
Hi,
Thanks for the info.
In our Linux machine, we don't have /usr/share/zoneinfo . Should we
install the timezone RPM for the same ?
Thanks,
Sarika
> -----Original Message-----
> From: linux-admin-owner@vger.kernel.org
> [mailto:linux-admin-owner@vger.kernel.org] On Behalf Of Horia
> Chirculescu
> Sent: Tuesday, June 03, 2003 2:22 PM
> To: Sarika Inamdar
> Cc: linux-admin@vger.kernel.org
> Subject: Re: Need to set TIMEZONE in Linux
>
>
> See the attached html file. It is a small document that
> covers the issue.
>
> Have a nice day.
>
> ____ ____ o ~
> // // / __ \ // \ // //'''' //\\
> //_____// / / / / //___ / // // // \\
> // // / /_/ / // \ // // //____\\
> // // \____/ // \ // \\.... // \\
>
> --------------------------------------------------------------
> ----------
> Comtec Net Romania
> ----------------------------------------------------
> WEB: www.eltop.ro IRC: irc.eltop.ro NEWS: news.eltop.ro
> ----------------------------------------------------
> Horia Chirculescu root@eltop.ro
> Connex: +40 723 205 086
> Zapp: +40 788 374 059
>
> On Tue, 3 Jun 2003, Sarika Inamdar wrote:
>
> > Hi All,
> >
> > We need to set the timezone for Linux. Its showing EDT as the time
> > zone. We need to set it to PST/GMT. How do I do this ?
> >
> > There is a file under /usr/share/zoneinfo/zone.tab . What
> does this do
> > ?
> >
> > We have a requirement, where a user during installation of
> appliaction
> > on Luinux, should be prompted for timezone change. What
> file needs to
> > be updated and which command should be used to set the timezone.
> >
> > Thanks in Advance for the help,
> > Sarika
> > -
> > To unsubscribe from this list: send the line "unsubscribe
> linux-admin"
> > in the body of a message to majordomo@vger.kernel.org More
> majordomo
> > info at http://vger.kernel.org/majordomo-info.html
> >
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Need to set TIMEZONE in Linux
2003-06-03 9:52 ` Sarika Inamdar
@ 2003-06-03 9:55 ` oford
2003-06-03 10:19 ` Sarika Inamdar
0 siblings, 1 reply; 6+ messages in thread
From: oford @ 2003-06-03 9:55 UTC (permalink / raw)
To: sinamdar; +Cc: 'Horia Chirculescu', linux-admin
[-- Attachment #1: Type: text/plain, Size: 2791 bytes --]
On Tue, 2003-06-03 at 04:52, Sarika Inamdar wrote:
> Hi,
>
> Thanks for the info.
>
> In our Linux machine, we don't have /usr/share/zoneinfo . Should we
> install the timezone RPM for the same ?
>
> Thanks,
> Sarika
>
> > -----Original Message-----
> > From: linux-admin-owner@vger.kernel.org
> > [mailto:linux-admin-owner@vger.kernel.org] On Behalf Of Horia
> > Chirculescu
> > Sent: Tuesday, June 03, 2003 2:22 PM
> > To: Sarika Inamdar
> > Cc: linux-admin@vger.kernel.org
> > Subject: Re: Need to set TIMEZONE in Linux
> >
> >
> > See the attached html file. It is a small document that
> > covers the issue.
> >
> > Have a nice day.
> >
> > ____ ____ o ~
> > // // / __ \ // \ // //'''' //\\
> > //_____// / / / / //___ / // // // \\
> > // // / /_/ / // \ // // //____\\
> > // // \____/ // \ // \\.... // \\
> >
> > --------------------------------------------------------------
> > ----------
> > Comtec Net Romania
> > ----------------------------------------------------
> > WEB: www.eltop.ro IRC: irc.eltop.ro NEWS: news.eltop.ro
> > ----------------------------------------------------
> > Horia Chirculescu root@eltop.ro
> > Connex: +40 723 205 086
> > Zapp: +40 788 374 059
> >
> > On Tue, 3 Jun 2003, Sarika Inamdar wrote:
> >
> > > Hi All,
> > >
> > > We need to set the timezone for Linux. Its showing EDT as the time
> > > zone. We need to set it to PST/GMT. How do I do this ?
> > >
> > > There is a file under /usr/share/zoneinfo/zone.tab . What
> > does this do
> > > ?
> > >
> > > We have a requirement, where a user during installation of
> > appliaction
> > > on Luinux, should be prompted for timezone change. What
> > file needs to
> > > be updated and which command should be used to set the timezone.
> > >
> > > Thanks in Advance for the help,
> > > Sarika
> > > -
> > > To unsubscribe from this list: send the line "unsubscribe
> > linux-admin"
> > > in the body of a message to majordomo@vger.kernel.org More
> > majordomo
> > > info at http://vger.kernel.org/majordomo-info.html
> > >
> >
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Some distros use(d) /usr/lib/zoneinfo. Try that before installing anything.
This rpm seems to fit the bill.
http://rpmfind.net/linux/rpm2html/search.php?query=zoneinfo
--
Owen Ford <oford@ev1.net>
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Need to set TIMEZONE in Linux
2003-06-03 9:55 ` oford
@ 2003-06-03 10:19 ` Sarika Inamdar
0 siblings, 0 replies; 6+ messages in thread
From: Sarika Inamdar @ 2003-06-03 10:19 UTC (permalink / raw)
To: 'oford'; +Cc: 'Horia Chirculescu', linux-admin
There is no zoneinfo in /usr/lib as well.
Can I go ahead and install the zoneinfo rpm. What do I need to set after
that ?
Should I create a link to /etc/localtime ?
Thanks,
Sarika
> -----Original Message-----
> From: linux-admin-owner@vger.kernel.org
> [mailto:linux-admin-owner@vger.kernel.org] On Behalf Of oford
> Sent: Tuesday, June 03, 2003 3:25 PM
> To: sinamdar@cisco.com
> Cc: 'Horia Chirculescu'; linux-admin@vger.kernel.org
> Subject: RE: Need to set TIMEZONE in Linux
>
>
> On Tue, 2003-06-03 at 04:52, Sarika Inamdar wrote:
> > Hi,
> >
> > Thanks for the info.
> >
> > In our Linux machine, we don't have /usr/share/zoneinfo . Should we
> > install the timezone RPM for the same ?
> >
> > Thanks,
> > Sarika
> >
> > > -----Original Message-----
> > > From: linux-admin-owner@vger.kernel.org
> > > [mailto:linux-admin-owner@vger.kernel.org] On Behalf Of Horia
> > > Chirculescu
> > > Sent: Tuesday, June 03, 2003 2:22 PM
> > > To: Sarika Inamdar
> > > Cc: linux-admin@vger.kernel.org
> > > Subject: Re: Need to set TIMEZONE in Linux
> > >
> > >
> > > See the attached html file. It is a small document that
> > > covers the issue.
> > >
> > > Have a nice day.
> > >
> > > ____ ____ o ~
> > > // // / __ \ // \ // //'''' //\\
> > > //_____// / / / / //___ / // // // \\
> > > // // / /_/ / // \ // // //____\\
> > > // // \____/ // \ // \\.... // \\
> > >
> > > --------------------------------------------------------------
> > > ----------
> > > Comtec Net Romania
> > > ----------------------------------------------------
> > > WEB: www.eltop.ro IRC: irc.eltop.ro NEWS: news.eltop.ro
> > > ----------------------------------------------------
> > > Horia Chirculescu root@eltop.ro
> > > Connex: +40 723 205 086
> > > Zapp: +40 788 374 059
> > >
> > > On Tue, 3 Jun 2003, Sarika Inamdar wrote:
> > >
> > > > Hi All,
> > > >
> > > > We need to set the timezone for Linux. Its showing EDT
> as the time
> > > > zone. We need to set it to PST/GMT. How do I do this ?
> > > >
> > > > There is a file under /usr/share/zoneinfo/zone.tab . What
> > > does this do
> > > > ?
> > > >
> > > > We have a requirement, where a user during installation of
> > > appliaction
> > > > on Luinux, should be prompted for timezone change. What
> > > file needs to
> > > > be updated and which command should be used to set the timezone.
> > > >
> > > > Thanks in Advance for the help,
> > > > Sarika
> > > > -
> > > > To unsubscribe from this list: send the line "unsubscribe
> > > linux-admin"
> > > > in the body of a message to majordomo@vger.kernel.org More
> > > majordomo
> > > > info at http://vger.kernel.org/majordomo-info.html
> > > >
> > >
> > -
> > To unsubscribe from this list: send the line "unsubscribe
> linux-admin"
> > in the body of a message to majordomo@vger.kernel.org More
> majordomo
> > info at http://vger.kernel.org/majordomo-info.html
>
> Some distros use(d) /usr/lib/zoneinfo. Try that before
> installing anything.
>
> This rpm seems to fit the bill.
>
http://rpmfind.net/linux/rpm2html/search.php?query=zoneinfo
--
Owen Ford <oford@ev1.net>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2003-06-03 10:19 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2003-06-03 8:44 Need to set TIMEZONE in Linux Sarika Inamdar
2003-06-03 8:49 ` oford
2003-06-03 8:52 ` Horia Chirculescu
2003-06-03 9:52 ` Sarika Inamdar
2003-06-03 9:55 ` oford
2003-06-03 10:19 ` Sarika Inamdar
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