Daylight savings time.

Daylight savings time.

[Alex Snow]

Hi All,
since tonight is daylight savings time I was wondering how to get my linux
box to change  into the edt timezone -0400 instead of the est timezone
-0500?

--
A message from the system administrator: "I've upped my priority, now up yours!"

Re: Daylight savings time.

[Jacob Schmude]

Hi
Well, all you have to do is to leave your box running. It'll do it for you
automatically, provided your timezone is set to one that supports it. I
know US/Eastern supports it as that's the timezone I use. I've seen it
automatically change if the box was shut down, but sometimes that doesn't
work. In short, leave linux on and you won't have to touch it.
Note that  even if, for some odd reason, linux doesn't change it for you,
most computer HW clocks, if set to localtime (not gmt) will also take care
of it.


On Sat, 5 Apr 2003, Alex Snow wrote:

> Hi All,
> since tonight is daylight savings time I was wondering how to get my linux
> box to change  into the edt timezone -0400 instead of the est timezone
> -0500?

Re: Daylight savings time.

[Igor Gueths]

Alex just run ntpdate.

May you code in the power of the source,
may the kernel, libraries, and utilities be with you,
throughout all distributions until the end of the epoch.

On Sat, 5 Apr 2003, Alex Snow wrote:

> Hi All,
> since tonight is daylight savings time I was wondering how to get my linux
> box to change  into the edt timezone -0400 instead of the est timezone
> -0500?
>
> --
> A message from the system administrator: "I've upped my priority, now up yours!"
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>

Re: Daylight savings time.

[Adam Myrow]

As explained in the clock Mini-howto, Linux doesn't care what time is in
the computer once it's going.  The only dealings with the hardware clock
are at startup, when it sets its time from the hardware clock and at
shutdown, when it writes the current time back to the hardware clock.
That's why when you install Linux, it asks not only what timezone you are
in, but whether your hardware clock is set to Universal time or local
time.  If the clock is set to local time, the hwclock command checks your
timezone and adds the right number of hours to get UTC, and assumes your
clock is right.  So, if you have your PC shut down during the DST switch,
and it doesn't do the change itself, your clock will be off by one hour.
If the PC was on during the switch, Linux converts since it just runs in
UTC internally and knows that DST came so it will show the right time.  At
shutdown or reboot, the correct time gets written back to the hardware
clock so it will once again, be in sync.  If you set your hardware clock
to UTC, the computer shouldn't attempt to adjust for DST since UTC doesn't
have it.  If your computer is turned off in that case, it makes no
difference.  As long as the clock reads correctly in terms of UTC, Linux
will come up with the right local time.

As I said, this comes from the Clock Mini-howto, and it really does a good
job of explaining how it works.  The whole issue comes up because Linux is
acting like all other Unix systems which always run in UTC and just
convert to get local time.  Of course, DOS and Windows want local time
because they don't do conversions.  They ask for your local timezone so
that they can put it in outgoing emails, and that's about it.  BTW, if you
have a dual boot system, and Windows is set to automatically adjust for
daylight savings time, you should either turn that off in Windows and
leave the computer on, or leave it on in Windows and leave the computer
off.  The Clock Mini-howto states that a Linux-only computer should keep
its clock in UTC, and it makes sense with this explanation.  Hope this
helps.

Re: Daylight savings time.

[Alex Snow]

Hi.
Thanks for the info.  I'm running multiple servers on this machine so it's
up pretty much 24/7.

--
A message from the system administrator: "I've upped my priority, now up yours!"
On Sat, 5 Apr 2003, Jacob Schmude wrote:

> Hi
> Well, all you have to do is to leave your box running. It'll do it for you
> automatically, provided your timezone is set to one that supports it. I
> know US/Eastern supports it as that's the timezone I use. I've seen it
> automatically change if the box was shut down, but sometimes that doesn't
> work. In short, leave linux on and you won't have to touch it.
> Note that  even if, for some odd reason, linux doesn't change it for you,
> most computer HW clocks, if set to localtime (not gmt) will also take care
> of it.
>
>
> On Sat, 5 Apr 2003, Alex Snow wrote:
>
> > Hi All,
> > since tonight is daylight savings time I was wondering how to get my linux
> > box to change  into the edt timezone -0400 instead of the est timezone
> > -0500?
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>

Re: Daylight savings time.

[Alex Snow]

Hi Igor,
Thanks for the info.  I'll see if it does it automatically and if not I'll
run ntpdate.

--
A message from the system administrator: "I've upped my priority, now up yours!"
On Sat, 5 Apr 2003, Igor Gueths wrote:

> Alex just run ntpdate.
>
> May you code in the power of the source,
> may the kernel, libraries, and utilities be with you,
> throughout all distributions until the end of the epoch.
>
> On Sat, 5 Apr 2003, Alex Snow wrote:
>
> > Hi All,
> > since tonight is daylight savings time I was wondering how to get my linux
> > box to change  into the edt timezone -0400 instead of the est timezone
> > -0500?
> >
> > --
> > A message from the system administrator: "I've upped my priority, now up yours!"
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
>
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>