Hi All,

I have a problem in synchronizing the time in LAN and WAN in our system.

Only one of my system is connected to the WAN and the other systems in
the LAN get their time from the NTP server running in the main system.

I have two problems in this setup.

1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
timezone information?? )
2. When ever the time zone is changed in the main system ,how to
update it in the systems connected in the LAN.

Forgive me if I am absurd since i am new to NTP.

Regards
Deepak

>>> In article <cbaa36330805220104k30c5a601gf0cad681150e3356@mail.gmail.com>, peerlessdeepaks@gmail.com (Deepak Pandian) writes:

Deepak> 1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
Deepak> timezone information?? )

NTP knows nothing about timezone information.

Deepak> 2. When ever the time zone is changed in
Deepak> the main system ,how to update it in the systems connected in the
Deepak> LAN.

That should be handled by the OS patch mechanism.
-- 
Harlan Stenn <stenn@ntp.org>
http://ntpforum.isc.org  - be a member!

Deepak Pandian wrote:
> Hi All,
> 
> I have a problem in synchronizing the time in LAN and WAN in our system.
> 
> Only one of my system is connected to the WAN and the other systems in
> the LAN get their time from the NTP server running in the main system.
> 
> I have two problems in this setup.
> 
> 1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
> timezone information?? )

No!  NTP deals in UTC only!  Your O/S is responsible for handling local 
time.

> 2. When ever the time zone is changed in the main system ,how to
> update it in the systems connected in the LAN.
> 

UTC ONLY!!!!

> Forgive me if I am absurd since i am new to NTP.
> 
> Regards
> Deepak

On 2008-05-22, Deepak Pandian <peerlessdeepaks@gmail.com> wrote:

> Only one of my system is connected to the WAN and the other systems in
> the LAN get their time from the NTP server running in the main system.
>
> I have two problems in this setup.

You have a misunderstanding of how NTP works.

> 1.The timeZone is always UTC in the LAN (Isn't it NTP's job to update
> timezone information?? )
>
> 2. When ever the time zone is changed in the main system ,how to
> update it in the systems connected in the LAN.

NTP synchronizes clocks to a common time-base across a network. The most
commonly used time-base is UTC.

Most OS clocks are set to UTC. Display of this time in the correct time
zone is handled by the appropriate userland, or system, utilities. Time
zone changes are handled by the tools included with your OS.

-- 
Steve Kostecke <kostecke@ntp.org>
NTP Public Services Project - http://support.ntp.org/

Hi,

Thanks .


> Most OS clocks are set to UTC. Display of this time in the correct time
> zone is handled by the appropriate userland, or system, utilities. Time
> zone changes are handled by the tools included with your OS.
>


It seems the OS reads the time zone information from a configured
file.Is there any other protocol which can instruct the clients
connected to it on timezone.

Regards
Deepak

Deepak Pandian wrote:

> 
> It seems the OS reads the time zone information from a configured
> file.Is there any other protocol which can instruct the clients
> connected to it on timezone.

This depends on the OS.  Some will require a reboot after such a change, 
as the file is read into an environment variable during startup. Others 
read the file every time.  Some of those actually use a link to the file.

For Windows, there may be something in group policies management, but 
note that the timezone is a property of each user.

For Unix, any tool for remotely updating files, e.g. ftp, sftp, rsync, 
or even rsh, telnet, ssh, might be appropriate.

Note that Unix users can override the timezone in their initialisation 
scripts, and you cannot predict how they will do this.

Actually, why do you want to do this?  For a normal modern Unix system, 
using the Olsen package,  you should be setting the timezone when you 
install the system and updating the timezone database files when a 
significant legislation change changes the rules.  Note, messing with 
the timezone files yourself may mean that an upgrade fails to update the 
file you've played with.

Older Unix systems normally only need updating with legislation changes 
(provided you can specify the rules in terms of nth week or last week, 
but, unlike Olsen based systems, you cannot specify rule changes into 
the indefinite future.

For Windows, legislation changes are implemented using Windows Update.

If you are trying to move the clock an hour twice a year, with any 
operating capable of running ntpd, you are not using it properly.

David Woolley wrote:
> 
> Older Unix systems normally only need updating with legislation changes 
> (provided you can specify the rules in terms of nth week or last week, 
> but, unlike Olsen based systems, you cannot specify rule changes into 
> the indefinite future.
> 
> For Windows, legislation changes are implemented using Windows Update.
> 

You can also use tools to update the timezone information. I needed to 
do this for W2K as it was not supported without a maintenance contract. 
I forget the name of the tool but it's in the resource kit.

Danny

peerlessdeepaks@gmail.com (Deepak Pandian) writes:

>Hi All,

>I have a problem in synchronizing the time in LAN and WAN in our system.

>Only one of my system is connected to the WAN and the other systems in
>the LAN get their time from the NTP server running in the main system.

>I have two problems in this setup.

>1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
>timezone information?? )

ntp operates on UTC. It is the job of the system to translate UTC to local
time zone information. (Yes, I know Windows is ignorant of such things).

>2. When ever the time zone is changed in the main system ,how to
>update it in the systems connected in the LAN.

Time zone information is not ntp's job.



>Forgive me if I am absurd since i am new to NTP.

Not absurd. Just running windows (which may or may not be absurd) whose
timekeeping leaves something to be desired. 

peerlessdeepaks@gmail.com (Deepak Pandian) writes:

>Hi,

>Thanks .


>> Most OS clocks are set to UTC. Display of this time in the correct time
>> zone is handled by the appropriate userland, or system, utilities. Time
>> zone changes are handled by the tools included with your OS.
>>


>It seems the OS reads the time zone information from a configured
>file.Is there any other protocol which can instruct the clients
>connected to it on timezone.

Yes. There cannot be. ntp is used to synchronize clocks where one is in
Ulan Bator and the other if Ohio-- if they tried to use timezone info, this
could not be done reasonably. Under many operating systems, the system
clock is also in UTC making synchronization easy. Windows, following DOS
decided to use local time, which causes may difficulties. ntp has to kludge
it. 
 

>Regards
>Deepak

Unruh wrote:
> peerlessdeepaks@gmail.com (Deepak Pandian) writes:
> 
>> Hi All,
> 
>> I have a problem in synchronizing the time in LAN and WAN in our system.
> 
>> Only one of my system is connected to the WAN and the other systems in
>> the LAN get their time from the NTP server running in the main system.
> 
>> I have two problems in this setup.
> 
>> 1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
>> timezone information?? )
> 
> ntp operates on UTC. It is the job of the system to translate UTC to local
> time zone information. (Yes, I know Windows is ignorant of such things).
> 

Nope. Windows also uses UTC and converts based on the time zone. ntpd 
works fine on Windows systems.

Danny

Unruh wrote:
[]
> ntp operates on UTC. It is the job of the system to translate UTC to
> local time zone information. (Yes, I know Windows is ignorant of such
> things).


Unruh,

Like many OSes, Windows uses UTC internally and translates it to the time 
zone specified by the user for display.  Start, Control Panel, Date and 
Time, Time Zone provides the user interface for this, and there are 
programs like TZedit which allow you to alter the registry settings 
controlling winter and summer local-to-UTC rules.

  http://download.microsoft.com/download/5/8/a/58a208b7-7dc7-4bc7-8357-28e29cdac52f/tzedit.exe

This is the third time you have provided incorrect information about 
Windows.

Thanks,
David 

"David J Taylor" <david-taylor@blueyonder.neither-this-bit.nor-this-bit.co.uk> writes:

>Unruh wrote:
>[]
>> ntp operates on UTC. It is the job of the system to translate UTC to
>> local time zone information. (Yes, I know Windows is ignorant of such
>> things).


>Unruh,

>Like many OSes, Windows uses UTC internally and translates it to the time 
>zone specified by the user for display.  Start, Control Panel, Date and 
>Time, Time Zone provides the user interface for this, and there are 
>programs like TZedit which allow you to alter the registry settings 
>controlling winter and summer local-to-UTC rules.

>  http://download.microsoft.com/download/5/8/a/58a208b7-7dc7-4bc7-8357-28e29cdac52f/tzedit.exe

>This is the third time you have provided incorrect information about 
>Windows.

I will try to improve.


>Thanks,
>David 

David J Taylor wrote:

> Like many OSes, Windows uses UTC internally and translates it to the time 
> zone specified by the user for display.  Start, Control Panel, Date and 
> Time, Time Zone provides the user interface for this, and there are 
> programs like TZedit which allow you to alter the registry settings 
> controlling winter and summer local-to-UTC rules.

Where does this legend stem from ?

There seems to be a difference in what TZ the RTC reflects.
( At least the SuSE installer regularly ask if the RTC shows
UTC or Local Time )

uwe

Uwe Klein wrote:
> David J Taylor wrote:
> 
>> Like many OSes, Windows uses UTC internally and translates it to the 
>> time zone specified by the user for display.  Start, Control Panel, 
>> Date and Time, Time Zone provides the user interface for this, and 
>> there are programs like TZedit which allow you to alter the registry 
>> settings controlling winter and summer local-to-UTC rules.
> 
> Where does this legend stem from ?

Windows.  Specifically Windows 3.x, 95, 98, ME, and 98SE. Also MS-DOS 
(these versions of Windows are really DOS extenders).  These are all 
basically single timezone systems.  Even NT (i.e. NT, 2000, 2003, XP, 
Vista) stores filesystem times in local time, at least for FAT and VFAT.
> 
> There seems to be a difference in what TZ the RTC reflects.
> ( At least the SuSE installer regularly ask if the RTC shows
> UTC or Local Time )

Windows continues to default to RTC = local time, partly for consistency 
and partly because they are optimised for ordinary people, who have 
problems with the concept of UTC, even in the UK.  (I failed to convince 
the managing committee of my block of flats that electromechanical solar 
time lighting control clocks were not supposed to be reset when the 
clocks changed!)

Uwe Klein wrote:
> David J Taylor wrote:
>
>> Like many OSes, Windows uses UTC internally and translates it to the
>> time zone specified by the user for display.  Start, Control Panel,
>> Date and Time, Time Zone provides the user interface for this, and
>> there are programs like TZedit which allow you to alter the registry
>> settings controlling winter and summer local-to-UTC rules.
>
> Where does this legend stem from ?

It's not a legend - it's directly what you get from calls to the OS.

  http://msdn.microsoft.com/en-us/library/ms724390(VS.85).aspx

and, for example, the need to use the GetLocalTime function to convert 
that value into local time:

  http://msdn.microsoft.com/en-us/library/ms724950(VS.85).aspx


> There seems to be a difference in what TZ the RTC reflects.
> ( At least the SuSE installer regularly ask if the RTC shows
> UTC or Local Time )
>
> uwe

The RTC runs in local time.

Cheers,
David 

Thank you very much for the info ( from David� )

My last "intimate" contact to 'Windows was with win3.1/NVdos7
( and that system still lives )
I've changed over to Unix/Linux in ~95.

uwe

Uwe Klein wrote:
> Thank you very much for the info ( from David� )
>
> My last "intimate" contact to 'Windows was with win3.1/NVdos7
> ( and that system still lives )
> I've changed over to Unix/Linux in ~95.
>
> uwe

You're welcome Uwe.  I started with Windows NT in 1992, having come from a 
background of VMS various UNIX environments, CP/M, DOS and Windows 3.x. 
It's the 32-bit version of Windows which has been my main environment for 
the past 15 years, though, and it's a pleasure to program and use (for me, 
at least).

Cheers,
David