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From: Jesse Pollard <jesse@cats-chateau.net>
To: David Balazic <david.balazic@uni-mb.si>, linux-kernel@vger.kernel.org
Subject: Re: Wrong clock initialization
Date: Wed, 21 May 2003 06:38:19 -0500
References: <3ECA673F.7B3FB388@uni-mb.si>
In-Reply-To: <3ECA673F.7B3FB388@uni-mb.si>
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On Tuesday 20 May 2003 12:34, David Balazic wrote:
> Hi!
>
> When the kernel is booted ( ia32 version at least ) , it reads
> the time from from the hardware CMOS clock , _assumes_ it is in
> UTC and set the system time to it.
>
> As almost nobody runs their clock in UTC, this means that the system
> is running on wrong time until some userspace tool corrects it.
>
> This can lead to situtation when time goes backwards :
>
> timezone is 2hours east of UTC.
> UTC time : 20:00
> local time : 22:00
>
> System time between boot and userspace fix : 22:00UTC
> System time after fix : 20:00UTC
>
> Comments ?

I strongly recommend running in UTC.

1. the system can then move between time zones without additional complexity
2. conversion errors during localtime -> system time don't occur
3. your clock doesn't get blown during system->localtime during shutdown
   (assuming you save system time...)
4. if you operate in a daylight saving time area, you won't get your clock
   blowin by variations in time depending on when you reboot.
-
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