Slightly OT: Atomic Clocks

WWVB broadcasts a daylight bit starting at 00:00 UTC for that day.
The clock has to receive it, and then remember it without acting on
it for some number of hours until 2 in the morning local time; then
set itself forward; and then manage to avoid stumbling over the logic
to achieve this for the rest of the day.

La Crosse atomic wall clocks all set themselves back to standard time
in the spring as soon as it's the next UTC day, in a fairly spectacular
chip design bug. It's correct again the following local day.

In particular though, the clock itself doesn't know about the calendar
but just follows the daylight bit as broadcast, and a little local
processing that may be wrong.
--
Ron Hardin
[email hidden]

On the internet, nobody knows you're a jerk.

Onefred said:

Hey,
I know this is a tad OT, but I also know that you are the type that take
notice of these things and probably already have done a little research
into the matter.
Last weekend, there was a TMBRA series mtn bike race about two hours
northwest of Dallas in St. Jo, TX. It was a relaxing 7 hour drive of
mostly flower covered highways. It was just what the doctored ordered!
Anyway, I brought my atomic alarm clock and, before going to sleep, set
it forward one hour just incase there was no reception in my hotel room.
To cut to the chase, one hour before the race I telephoned my wife to
see how everyone was doing. I was on the road in route to the race and
the first thing that comes out of her mouth is "What are you doing?"
"I'm going to the competition to warm-up and get ready.What else would I
be doing?", I replied. "I don't know what time it is there, but here
it's 8:30", she explained. "Are you sure?" "Yes, the television station
shows 8:30!" Suddenly, I had a terrible case of tunnel vision and was in
disbelief of the circumstances... "Holy fauking shee-ite!", I thought.
It wasn't one hour before the race -- it was the start-time of the race!
My gauddamn clock set itself back!!! Well, needless to say, I rushed as
fast as I could and got to the starting line an incredibly spirit-
dampening 17 minutes after my group had left. I started w/ the last
men's group which was better than having to start w/the ladies who were
all lined up after us waiting for their start! I was really excited when
I finally reached the last rider in my group, but he was riding at what
seemed like -5 MPH. He may as well have been going in reverse!!
Something was obviously wrong, so I asked him how he was feeling. "Not
great. I have leg cramps.", he said. I quickly lost my grin when I
realized he probably wouldn't even finish... I managed to pass a few
more in my group and was happy not to finish last.
Sigh. Well, the course was super fast. It was the first dry one of this
race season and the weather was nice. So I still had a blast, and that's
a good thing.
But back to the atomic clock problem. Mine didn't change to the correct
hour until Monday morning!!! What is the point of having an atomic alarm
clock if it does not change the hour automatically when daylight savings
comes and goes??? So that I wake up at exactly the same second every
morning??? Now, that's laughable!
The amazing thing to learn from this experience was that NASA engineers
don't need to get to work on time until a few days after we non-NASA
folk do! I guess their communications satellites don't need to know the
correct time until Monday, too. I thought it was Federal law that
required us to observe daylight savings, so why wouldn't the government
have it right? Maybe the government employee who is responsible for
setting their official clock was late getting to work to set it forward
one hour. Now wouldn't that be appropriate!!
I am harboring really nasty feelings towards my alarm clock and half of
me wants to throw it into a brick wall, or run over it w/ my car, but my
other half knows that this would be unreasonable.
Dave

Dear Dave,

This sounds like another reason to prefer solar over nuclear.

Carl Fogel

--

onefred said:

But back to the atomic clock problem. Mine didn't change to the correct
hour until Monday morning!!! What is the point of having an atomic alarm
clock if it does not change the hour automatically when daylight savings
comes and goes??? So that I wake up at exactly the same second every
morning??? Now, that's laughable!

The amazing thing to learn from this experience was that NASA engineers
don't need to get to work on time until a few days after we non-NASA folk
do! I guess their communications satellites don't need to know the

correct

Quoted message said:

time until Monday, too. I thought it was Federal law that required us to
observe daylight savings, so why wouldn't the government have it right?
Maybe the government employee who is responsible for setting their

official

Quoted message said:

clock was late getting to work to set it forward one hour. Now wouldn't
that be appropriate!!

Two comments:

1) Complex systems fail in complex ways.

2) Daylight savings time is a bogus idea. Take no notice of it. It's for
idiots!

Back to the atomic clock. The clock gets a signal from station WWVB in Fort
Collins, CO. WWVB operates on the ungodly frequency of 60 kHz. Since the "D"
layer of the ionosphere absorbs low frequency RF during daylight hours, the
clock will only get the WWVB signal at night (if you're lucky, and depending
where you live.) This is probably not the best clock to use if you have an
important event that you don't want to miss. Atomic clocks work best when
you set them up in a fixed location, and then don't mess with them.

Here's a picture of the WWVB transmitting site:

http://www.boulder.nist.gov/timefreq/stations/wwvb.htm

Art Harris N2AH

"Arthur Harris" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

onefred said:

But back to the atomic clock problem. Mine didn't change to the correct
hour until Monday morning!!! What is the point of having an atomic

alarm

Quoted message said:

Quoted message said:

clock if it does not change the hour automatically when daylight savings
comes and goes??? So that I wake up at exactly the same second every
morning??? Now, that's laughable!

The amazing thing to learn from this experience was that NASA engineers
don't need to get to work on time until a few days after we non-NASA

folk

Quoted message said:

Quoted message said:

do! I guess their communications satellites don't need to know the

correct

Quoted message said:

time until Monday, too. I thought it was Federal law that required us

to

Quoted message said:

Quoted message said:

observe daylight savings, so why wouldn't the government have it right?
Maybe the government employee who is responsible for setting their

official

Quoted message said:

clock was late getting to work to set it forward one hour. Now wouldn't
that be appropriate!!

Two comments:

1) Complex systems fail in complex ways.

2) Daylight savings time is a bogus idea. Take no notice of it. It's for
idiots!

I agree wholeheartedly.

Dave

"Benjamin Weiner" <[email hidden]> wrote in message
news:40772bb4$1@darkstar...

Quoted message said:

onefred said:

The amazing thing to learn from this experience was that NASA engineers
don't need to get to work on time until a few days after we non-NASA

folk

Quoted message said:

Quoted message said:

do! I guess their communications satellites don't need to know the

correct

Quoted message said:

Quoted message said:

time until Monday, too. I thought it was Federal law that required us

to

Quoted message said:

Quoted message said:

observe daylight savings, so why wouldn't the government have it right?
Maybe the government employee who is responsible for setting their

official

Quoted message said:

Quoted message said:

clock was late getting to work to set it forward one hour. Now wouldn't
that be appropriate!!

WTF are you talking about. "Federal law"? There are two and a half
states that don't use any Daylight Savings Time at all.

Yes, but didn't they have to amend their state constitutions to get around
it? I don't recall exactly but this sounds familiar.

Quoted message said:

I had never heard of "atomic alarm clocks" until now, and a little
Google research. Of course, they are not "atomic clocks" in any
meaningful sense. They're radio-controlled clocks tuned to a time
standard. If the maker of your clock can't manage to make it
update to WWV properly, don't blame the government. What do you do
if you're in a place that gets bad reception on the time of the
DST switch - like a building with aluminum siding?

I don't know what NASA engineers prefer (NASA has nothing to do with
NIST or WWV, of course), but anyone who really needs to know what
time it is for serious purposes, especially space-based, is using UTC
anyway.

Quoted message said:

I am harboring really nasty feelings towards my alarm clock and half of

me

Quoted message said:

Quoted message said:

wants to throw it into a brick wall, or run over it w/ my car, but my

other

Quoted message said:

Quoted message said:

half knows that this would be unreasonable.

It sounds perfectly reasonable to me. Get a clock that operates
in a known fashion and remember to set the time your own self.

Wake-up on the wrong side of the bed this morning, Ben?

Dave

onefred said:

The amazing thing to learn from this experience was that NASA engineers
don't need to get to work on time until a few days after we non-NASA folk
do! I guess their communications satellites don't need to know the correct
time until Monday, too. I thought it was Federal law that required us to
observe daylight savings, so why wouldn't the government have it right?
Maybe the government employee who is responsible for setting their official
clock was late getting to work to set it forward one hour. Now wouldn't
that be appropriate!!

WTF are you talking about. "Federal law"? There are two and a half
states that don't use any Daylight Savings Time at all.

I had never heard of "atomic alarm clocks" until now, and a little
Google research. Of course, they are not "atomic clocks" in any
meaningful sense. They're radio-controlled clocks tuned to a time
standard. If the maker of your clock can't manage to make it
update to WWV properly, don't blame the government. What do you do
if you're in a place that gets bad reception on the time of the
DST switch - like a building with aluminum siding?

I don't know what NASA engineers prefer (NASA has nothing to do with
NIST or WWV, of course), but anyone who really needs to know what
time it is for serious purposes, especially space-based, is using UTC
anyway.

Quoted message said:

I am harboring really nasty feelings towards my alarm clock and half of me
wants to throw it into a brick wall, or run over it w/ my car, but my other
half knows that this would be unreasonable.

It sounds perfectly reasonable to me. Get a clock that operates
in a known fashion and remember to set the time your own self.

"onefred" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Arthur Harris" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

onefred said:

But back to the atomic clock problem. Mine didn't change to the

correct

Quoted message said:

Quoted message said:

Quoted message said:

hour until Monday morning!!! What is the point of having an atomic

alarm

Quoted message said:

Quoted message said:

clock if it does not change the hour automatically when daylight

savings

Quoted message said:

Quoted message said:

Quoted message said:

comes and goes??? So that I wake up at exactly the same second every
morning??? Now, that's laughable!

Perhaps your atomic clock works like mine:

It only checks once a day, around midnight. And since the time changes at
2am, it doesn't correct until the next night.

Bruce

onefred <[email hidden]> wrote: [deletia]

Quoted message said:

Quoted message said:

Quoted message said:

The amazing thing to learn from this experience was that NASA engineers
don't need to get to work on time until a few days after we non-NASA folk
do! I guess their communications satellites don't need to know the correct
time until Monday, too. I thought it was Federal law that required us to
observe daylight savings, so why wouldn't the government have it right?

Quoted message said:

Quoted message said:

I don't know what NASA engineers prefer (NASA has nothing to do with
NIST or WWV, of course), but anyone who really needs to know what
time it is for serious purposes, especially space-based, is using UTC
anyway.

Quoted message said:

Wake-up on the wrong side of the bed this morning, Ben?

I guess you mean it as funny, but it ticks me off when somebody
makes a mistake like failing to set their clock to the correct time
because of an over-reliance on cheap consumer electronics, and
then goes on a rant about NASA engineers and the government.
Don't blame the government for not getting you up in time.

Now if you want to blame anything on NASA _managers_, that would
be fine with me.

BTW, I had to wake up that morning to start (and score) an MTB race,
too. I went around the house at 10 pm the night before setting
the clocks forward. Even the ones in the car (why are there _two_
clocks in my car? Don't ask).

Benjamin Weiner said:

onefred said:

The amazing thing to learn from this experience was that NASA
engineers don't need to get to work on time until a few days after we
non-NASA folk do! I guess their communications satellites don't need
to know the correct time until Monday, too. I thought it was Federal
law that required us to observe daylight savings, so why wouldn't the
government have it right? Maybe the government employee who is
responsible for setting their official clock was late getting to work
to set it forward one hour. Now wouldn't that be appropriate!!

WTF are you talking about. "Federal law"? There are two and a half
states that don't use any Daylight Savings Time at all.
I had never heard of "atomic alarm clocks" until now, and a little
Google research. Of course, they are not "atomic clocks" in any
meaningful sense. They're radio-controlled clocks tuned to a time
standard. If the maker of your clock can't manage to make it update to
WWV properly, don't blame the government. What do you do if you're in a
place that gets bad reception on the time of the DST switch - like a
building with aluminum siding?
I don't know what NASA engineers prefer (NASA has nothing to do with
NIST or WWV, of course), but anyone who really needs to know what
time it is for serious purposes, especially space- based, is using
UTC anyway.

Quoted message said:

I am harboring really nasty feelings towards my alarm clock and half
of me wants to throw it into a brick wall, or run over it w/ my car,
but my other half knows that this would be unreasonable.

It sounds perfectly reasonable to me. Get a clock that operates in a
known fashion and remember to set the time your own self.

Federal law mandates states observe Daylight Savings Time UNLESS the
state legislature specifically votes to remain on Standard Time. If the
legislature does nothing, the state goes to daylight savings time. The
Federal law does have an escape clause that states at the western most
extreme of a time zone often exercise-usually to avoid the problems of
children travelling to school in the dark.

--

onefred wrote:

-snip my Atomic clock made me late for my race-

I like your tale a lot better than the guys who throw their
bicycles after a race and blame the mechanic.

--
Andrew the mechanic Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Benjamin Weiner said:

I said:

... If the maker of your clock can't manage to make it update to WWV
properly, don't blame the government. What do you do if you're in a
place that gets bad reception on the time of the DST switch - like a
building with aluminum siding?

On rereading the story, I saw that you had the opposite problem - you
did set the clock forward but it did get reception and reset itself (at
midnight, perhaps) to standard time. That's extra annoying - just dumb
firmware. I'm definitely in favor of your running the clock over now.
Hell, my cheap VCR manages to compute daylight savings time by itself
from day, date, and year.
One too many posts to this thread from me, sorry.

Dear Benjamin,

No, not too many posts--I'd hate to have missed this last one.

Most of us aren't willing to type "oops," much less "sorry."

Besides, it clarified the peculiar situation nicely for those of us who
still use sun dials.

Thanks for a good example.

Carl Fogel

--

I said:

... If the maker of your clock can't manage to make it
update to WWV properly, don't blame the government. What do you do
if you're in a place that gets bad reception on the time of the
DST switch - like a building with aluminum siding?

On rereading the story, I saw that you had the opposite problem -
you did set the clock forward but it did get reception and reset
itself (at midnight, perhaps) to standard time. That's extra
annoying - just dumb firmware. I'm definitely in favor of your
running the clock over now. Hell, my cheap VCR manages to compute
daylight savings time by itself from day, date, and year.

One too many posts to this thread from me, sorry.

onefred said:

"Arthur Harris" <[email hidden]> wrote in message

Quoted message said:

2) Daylight savings time is a bogus idea. Take no notice of it. It's for
idiots!

I agree wholeheartedly.

bah. i love daylight savings time. can't get enuf of it. i want mandatory
double year long daylight savings time.

... more daylight after work in which to bike.

stuff the mornings, i'm not up then. dawn should be at 9am .. when i start
to think about waking up.
--
david reuteler
[email hidden]

Ron Hardin said:

WWVB broadcasts a daylight bit starting at 00:00 UTC for that day.
The clock has to receive it, and then remember it without acting on
it for some number of hours until 2 in the morning local time; then
set itself forward; and then manage to avoid stumbling over the logic
to achieve this for the rest of the day.

(snip)

Quoted message said:

Ron Hardin
[email hidden]

On the internet, nobody knows you're a jerk.

True. There's a second bit too. The combination of the two tells
precisely what's going on with DST .... i.e. gonna come/go tomorrow.
Something like that anyway; it's been a while since I read the spec.

Some self-setting clocks do "phone home" (check NIST transmissions) only
once per 24 hours, so if your does, and if recpetion is dodgy then, your
clock clould fail to update its time and/or respect the coming/going of
DST. In certain parts of the US WWVB is difficult or impossible to
receive.

I have an Oregon Scientific RM-116E self-setter (it's a tabletop alarm
clock) and I *think* it checks in more than once per day. Not sure.

Later I did my own version of a WWVB clock, and I designed it to check
in every hour. Overkill, I know, but in the 3-4 years it's been running
I have never seen the wrong time displayed.

"Benjamin Weiner" <[email hidden]> wrote in message
news:40774bfc$1@darkstar...

Quoted message said:

onefred <[email hidden]> wrote: [deletia]

Quoted message said:

Quoted message said:

> The amazing thing to learn from this experience was that NASA

engineers

Quoted message said:

Quoted message said:

Quoted message said:

> don't need to get to work on time until a few days after we non-NASA

folk

Quoted message said:

Quoted message said:

Quoted message said:

> do! I guess their communications satellites don't need to know the

correct

Quoted message said:

Quoted message said:

Quoted message said:

> time until Monday, too. I thought it was Federal law that required

us to

Quoted message said:

Quoted message said:

Quoted message said:

> observe daylight savings, so why wouldn't the government have it

right?

Quoted message said:

Quoted message said:

Quoted message said:

I don't know what NASA engineers prefer (NASA has nothing to do with
NIST or WWV, of course), but anyone who really needs to know what
time it is for serious purposes, especially space-based, is using UTC
anyway.

Quoted message said:

Wake-up on the wrong side of the bed this morning, Ben?

I guess you mean it as funny, but it ticks me off when somebody
makes a mistake like failing to set their clock to the correct time
because of an over-reliance on cheap consumer electronics, and
then goes on a rant about NASA engineers and the government.

Hey, wait a second. NASA and other government employees often are the
object of ridicule and plesantry. It's meant in jest. I don't sincerely
feel that because someone works for the government, they are stupid.
Perhaps I just watch too much late night satire.

Also, I've some cheap consumer electronics that work like a charm. Not all
of us can afford to buy professional caliber stuff all of the time.

Quoted message said:

Don't blame the government for not getting you up in time.

[Oh God, give me strength...]

Quoted message said:

Now if you want to blame anything on NASA _managers_, that would
be fine with me.

Whoa. This an attempt at humor, Mr. Weiner? 'Cause you got a giggle out'a
me.

Quoted message said:

BTW, I had to wake up that morning to start (and score) an MTB race,
too. I went around the house at 10 pm the night before setting
the clocks forward. Even the ones in the car (why are there _two_
clocks in my car? Don't ask).

OK.

Dave