[9fans] Daylight savings time

[9fans] Daylight savings time

[Pietro Gagliardi]

Hello. How do you configure Plan 9 to support DST? I noticed that my
clock is wrong just now. Thanks.

Re: [9fans] Daylight savings time

[erik quanstrom]

> Hello. How do you configure Plan 9 to support DST? I noticed that my
> clock is wrong just now. Thanks.

dst is supported as long as your timezone is set correctly.
	echo $timezone|sed 1q
should give you the skinny on yout timezone.  the format is
	stdcode stdoffsetsec dstcode dstoffsetsec
for example, for athens. ga or any other place on the us east
cost, it should be
	EST -18000 EST EDT -14400
which says that during standard time, the offset from GMT is
-18000 seconds, or -5 hrs.  the offset during daylight savings time
is -4 hrs.  the rest of the file is pairs of offsets bracketing the
start and end of dst periods.  thus the only constraint on dst
periods is the offset from gmt can't change from period to period.

if your timezone is not correct, make sure the timezone files are
synced with sources and
	cp /adm/timezone/«yourtimezone» /adm/timezone/local
	ifs=() timezone=`{cat /adm/timezone/local}

- erik

Re: [9fans] Daylight savings time

[Pietro Gagliardi]

Thanks to both of you. I've been setting up virtual machines so many  
times that I forget these subtle things.

On Mar 22, 2008, at 2:06 PM, erik quanstrom wrote:

>> Hello. How do you configure Plan 9 to support DST? I noticed that my
>> clock is wrong just now. Thanks.
>
> dst is supported as long as your timezone is set correctly.
> 	echo $timezone|sed 1q
> should give you the skinny on yout timezone.  the format is
> 	stdcode stdoffsetsec dstcode dstoffsetsec
> for example, for athens. ga or any other place on the us east
> cost, it should be
> 	EST -18000 EST EDT -14400
> which says that during standard time, the offset from GMT is
> -18000 seconds, or -5 hrs.  the offset during daylight savings time
> is -4 hrs.  the rest of the file is pairs of offsets bracketing the
> start and end of dst periods.  thus the only constraint on dst
> periods is the offset from gmt can't change from period to period.
>
> if your timezone is not correct, make sure the timezone files are
> synced with sources and
> 	cp /adm/timezone/«yourtimezone» /adm/timezone/local
> 	ifs=() timezone=`{cat /adm/timezone/local}
>
> - erik
>
>

Re: [9fans] Daylight savings time

[a]

Copy the correct timezone file for your locale from /adm/timezone
into /adm/timezone/local. Reboot.

Re: [9fans] Daylight savings time

[Dave Eckhardt]

> Copy the correct timezone file for your locale from
> /adm/timezone into /adm/timezone/local.

Though if the file for your locale is updated from sources
(e.g., the recent U.S. DST change), the copy called "local"
won't change along with it.  I noticed last summer that
I was suffering from exactly that sequence of events.

I've wondered for a while about the advisability of
  bind /adm/timezone/US_Eastern /adm/timezone/local
in /lib/namespace.local.

Dave Eckhardt