Time Problem

[Patrick Smith]

Peter Bagnall wrote:
> MacOS and Linux use different ways of storing the time in the real time 
> clock. One (and I forget which way round this is) uses UCT and the other 
> uses local time. There is a way to force linux to do the same thing that 
> MacOS does.
> 
> On Friday, December 20, 2002, at 03:30 PM, Joe Villari wrote:
>> After upgrading my TI PowerBook from 2.1 to 2.3 I've developed a 
>> problem with the time. When ever I boot into YDL it gives me a time 
>> which is about either 5 hours before or after the current time. It's 
>> not consistent.
>>
>> I've tried resetting the time from within KDE but if I boot into MAC 
>> OS the time is incorrect again and when I reboot into YDL it's not 
>> right again. My time zones remain correct.

Mac OS 9 stores local time in the hardware clock.  Linux generally 
prefers to store UTC.  I'd assume Mac OS X can store UTC, given that 
it's also Unix.

As far as I know, there is no way to get OS 9 to store UTC.  So you need 
to get Linux to store local time.  The disadvantage of this is that 
you'll have to manually change the time when going to and from daylight 
savings.

Two things have to be done.  When Linux starts up and reads the hardware 
clock, it needs to know to read local time.  This can be done with the 
hwclock command.  Look for hwclock somewhere in the startup scripts and 
change the options appropriately (the man page will have details).

Second, when you change the time in Linux, you want it stored in local 
time.  There's probably a way to have this happen automatically, but I 
don't know how.  You can just run hwclock by hand every time you correct 
the time.

Myself, I use Mac OS so rarely that I just leave the hardware clock as 
UTC, and accept that the time will be wrong in Mac OS.  Plus I run ntpd, 
so the time is always correct without me having to fix it.
-- 
patsmith@pobox.com