James, On Thursday 05 May 2005 19:13, James Knott wrote:

Chris Carlen wrote:

...

Hi:

I am in Pacific timezone, but I don't know when it is supposed to be PST vs. PDT. ...

...

Is PDT correct for this time of year? Is this set automagically?

It would be PDT. The time changes in April & October. If your computer is set up correctly, it should change automatically.

My experience with recent OSes, including all of MacOS, Windows and Linux, is that they automatically adapt to the onset and termination of Daylight Saving Time (even my VCR does this, based on time signals embedded in TV broadcasts). My question is, how is this handled in Linux? Is it part of the NTP protocol, or must the dates be encoded in some configuration information somewhere? If it's the latter, how will the possible legislative change to the national DST start and end dates be accommodated in Linux software? Randall Schulz

Jerry Feldman wrote:

The only place where this does not work is in Indiana because they can't figure out what timezone they want to be in. (Parts of Indiana are in Eastern and do not adjust for DST, other parts are in Eastern and do adjust for DST, and parts are in Central and those do adjust. recently the Indiana legislature voted to use DST for the whole state, but part of the state will still; be Central while the rest will be Eastern.

http://www.timetemperature.com/tzus/indiana_time_zone.shtml

It's amazing how a country as technologically advanced as the U.S. can be so backward in so many things. Incidentally, at one time many farmers were against DST, as they claimed the "extra hour" of sunlight would burn crops. It appears that sort of thinking still exists. Some religious groups express similar backward ideas.

Randall R Schulz wrote:

James,

On Friday 06 May 2005 06:15, James Knott wrote:

...

...

Incidentally, at one time many farmers were against DST, as they claimed the "extra hour" of sunlight would burn crops. ...

I challenge you to produce documentation of such a claim ever having been made during the debate over daylight savings time.

http://www.ojaivalleynews.com/issues2003/04-April2003/04-11-03/04-11-03edito... " Our first bout with Daylight Stolen Time was during World War I, and it was quickly repealed after war's end. One Wisconsin legislator actually got on the floor of Congress and, in his testimony, pronounced against DST on the grounds that the extra hour of sunlight would burn the crops. Perhaps, in a delusion common to this nation's lawmakers, he actually thought that ordering the duration of the day was among the prerogatives of office. More power to him, then, that he chose to refuse to wield that authority."

On Fri, 2005-05-06 at 07:02 -0700, Randall R Schulz wrote:

James,

On Friday 06 May 2005 06:15, James Knott wrote:

...

...

Incidentally, at one time many farmers were against DST, as they claimed the "extra hour" of sunlight would burn crops. ...

I challenge you to produce documentation of such a claim ever having been made during the debate over daylight savings time.

I was a youngster when DST was going into affect and remember the same type of thing going on, the the farmers thought the "extra" hour of daylight would create problems. -- Ken Schneider UNIX since 1989, linux since 1994, SuSE since 1998 "The day Microsoft makes something that doesn't suck is probably the day they start making vacuum cleaners." -Ernst Jan Plugge

Randall R Schulz wrote:

Ken,

On Friday 06 May 2005 07:33, Ken Schneider wrote:

...

On Fri, 2005-05-06 at 07:02 -0700, Randall R Schulz wrote:

...

James,

On Friday 06 May 2005 06:15, James Knott wrote:

...

...

Incidentally, at one time many farmers were against DST, as they claimed the "extra hour" of sunlight would burn crops. ...

I challenge you to produce documentation of such a claim ever having been made during the debate over daylight savings time.

I was a youngster when DST was going into affect and remember the same type of thing going on, the the farmers thought the "extra" hour of daylight would create problems.

"Creating problems" does not equate with believing that DST would "burn the crops" (let alone believing the day would be lengthened).

I certainly hope these statements do not reflect an attitude about the intelligence typical of farmers, either today or a hundred years ago.

One thing I've noticed, is that many people will blindly accept an idea that "makes sense", even though if they gave it some thought, they'd realize it's nonsense. Religion is the greatest example of this. You might want to read Carl Sagan's "A Demon Haunted World" or "Voodoo Science", by Robert Park, for some examples of the nonsense many people believe. Or check out the supermarket rags. One thing that's apparently in very short supply, is critical thinking.

On Friday 06 May 2005 9:15 am, James Knott wrote:

Jerry Feldman wrote:

...

The only place where this does not work is in Indiana because they can't figure out what timezone they want to be in. (Parts of Indiana are in Eastern and do not adjust for DST, other parts are in Eastern and do adjust for DST, and parts are in Central and those do adjust. recently the Indiana legislature voted to use DST for the whole state, but part of the state will still; be Central while the rest will be Eastern.

http://www.timetemperature.com/tzus/indiana_time_zone.shtml

It's amazing how a country as technologically advanced as the U.S. can be so backward in so many things.

Incidentally, at one time many farmers were against DST, as they claimed the "extra hour" of sunlight would burn crops. It appears that sort of thinking still exists.

Some religious groups express similar backward ideas. There are many urban legends. Other than Indiana, Arizona and Hawaii do not use Daylight time. Good history here. Some of the complaints are included below. "The idea of daylight saving was first conceived by Benjamin Franklin (portrait at right) during his sojourn as an American delegate in Paris in 1784" http://webexhibits.org/daylightsaving/ Another complaint is sometimes put forth by people who wake at dawn, or whose schedules are otherwise tied to sunrise, such as farmers. Farmers often dislike the clocks changing mid year. Canadian poultry producer Marty Notenbomer notes, "The chickens do not adapt to the changed clock until several weeks have gone by so the first week of April and the last week of October are very frustrating for us."

In Israel, ultra-Orthodox Sephardic Jews have campaigned against daylight saving time because they recite Slikhot penitential prayers in the early morning hours during the Jewish month of Elul. A writer in 1947 wrote, "I don't really care how time is reckoned so long as there is some agreement about it, but I object to being told that I am saving daylight when my reason tells me that I am doing nothing of the kind. I even object to the implication that I am wasting something valuable if I stay in bed after the sun has risen. As an admirer of moonlight I resent the bossy insistence of those who want to reduce my time for enjoying it. At the back of the Daylight Saving scheme I detect the bony, blue-fingered hand of Puritanism, eager to push people into bed earlier, and get them up earlier, to make them healthy, wealthy and wise in spite of themselves." (Robertson Davies, The Diary of Samuel Marchbanks, 1947, XIX, Sunday.) -- Jerry Feldman Boston Linux and Unix user group http://www.blu.org PGP key id:C5061EA9 PGP Key fingerprint:053C 73EC 3AC1 5C44 3E14 9245 FB00 3ED5 C506 1EA9

The Friday 2005-05-06 at 08:32 -0400, Jerry Feldman wrote:

> > Is PDT correct for this time of year?  Is this set automagically?
> There are 2 answers:
> 1. If you set your system clock to UCT (which is the preferred method), your 
> time will update correctly even without using ntp as long as you don't have 
> much drift. 
> 
> 2. If you set your system clock to local time (because you dual boot with 
> Windows) I have found that without ntp, Linux does not update to daylight 
> time in April and revert in October. 

That's not correct. I have sat in front of my computer at the the exact 
moment that the daylight change should occur, and it does, correctly and 
smoothly. I don't have an ntp daemon, and I was not connected to the 
network at that moment.

Notice that internally, Linux always keeps UTC (not UCT), regardless of 
timezone settings. In fact, each user on the same machine may have a 
different time setting. The system is very simple: as UTC doesn't change, 
local time is calculated and daylight saving time applied appropriately, 
from the internal UTC, and printed for the user to see. For this, of 
course, the programmers must know how to calculate it in advance.

 Try it: 

    cer@nimrodel:~> TZ=UTC date
    Mon May  9 02:01:09 UTC 2005
    cer@nimrodel:~> date
    Mon May  9 04:01:13 CEST 2005
    cer@nimrodel:~> TZ=PST date
    Mon May  9 02:02:39 PST 2005
    cer@nimrodel:~> TZ=PDT date
    Mon May  9 02:02:46 PDT 2005
    cer@nimrodel:~>

  You can get any time on the fly - just by setting the TZ variable.


Notice also that when in Yast you use that configuration box that says 
"use local time" it only means that the CMOS clock (which is not the 
system time, but the battery cmos chip that keeps time with the computer 
off) keeps local time instead of UTC. It does not mean that system time 
will be local or UTC time: system time will always be UTC.


-- 
Cheers,
       Carlos Robinson