How do I set the OS clock to GMT in Snow Leopard and Leopard?

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Level 1

8 points

How do I set the OS clock to GMT in Snow Leopard and Leopard?

Can't find any results on the help topics or forum search. Google search only shows people trying to set the system clock AWAY from GMT.

My understanding is that the hardware clock is always in GMT. But the OS has no GMT option.

I've searched for city "Greenwich", searched for GMT, searched for Zulu, searched for UTC. All I can get is British time.

All of our production servers around the world (Solaris, Linux, Windows) run on GMT. I'd like to set our handful of XServes to the same.

XServe (Intel), Mac OS X (10.6.3)

Posted on Apr 28, 2010 10:52 AM

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Answer 1

Apr 28, 2010 10:59 AM in response to rconti

Try this command in terminal:

systemsetup -listtimezones

I see a GMT choice listed just under Europe/Zurich. If that's the setting you need:

systemsetup -settimezone GMT

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Answer 2

rconti Author

Level 1

8 points

Apr 28, 2010 12:04 PM in response to Sheri Nikishin

This is very helpful. Unfortunately, if you open Date and Time prefs after doing this, it sets the time to London time (no matter where you had it set in the UI before).

If you lock the time to London, then quit Date and Time prefs, then change it on the commandline, it prompts for password (thanks to the lock), but then opening date and time prefs sets it back to London.

Here was the solution for me:

Open Date and Time prefs. It sets clock to London. Go to the commandline, use "systemsetup -settimezone GMT". The time will now be set to GMT (in the upper right corner on the menubar) even though the Date and Time prefs that you left open still shows London. Click the lock button, then quit Date and Time prefs. The clock stays on GMT. If you open Date and Time prefs, the time stays set to GMT even though the map shows London.

thanks for your quick response!! Hopefully Apple gets on things and adds a GMT option at some point.

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Answer 3

Apr 28, 2010 12:56 PM in response to rconti

Hi

An International Decree set the prime meridian at Greenwich. Hence GMT = Greenwich Mean Time. Greenwich is in London.

Tony

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Answer 4

Apr 28, 2010 2:15 PM in response to Antonio Rocco

Mac OS X Server keeps its time internally as GMT already. You do not need to intervene in any way. Just set it using a Time Server and you are done. It can communicate worldwide without further intervention.

As a convenience to the humans involved, you can view the System Time as if it were Local Time. To do this, you set the Local Time Zone by specifying a city in your Time Zone. This sets up an illusion that will change the time stamp (by the appropriate number of time zones) and present time stamps as Local Time when appropriate.

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