Need clarification of terms for noon and midnight using PM and AM

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Gail M. Hall

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Dec 21, 2001, 11:34:37 PM12/21/01
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This is really telecom related because I'm looking at what kind of usage
"minutes" are called what and when.

Is there a consistent definition of 12:00 AM and 12:00 PM in the telecom
business?

Technically there is no such thing as 12:00 AM or PM. There is 12:00 noon
and 12:00 midnight. AM means before noon and PM means after noon, but
right at noon, it is straight-up noon.

It seems to me that it would be more clear if in the text defining times
the 24-hour format could be used, just as weight is expressed in metric and
US measures.

Here is a quote of the definition of night and weekend hours in a brochure
that I got.

"Night hours are 9:00 PM - 5:59 AM, Monday - Friday.
Weekend hours are 12:00 AM Saturday - 11:59 PM Sunday.
Peak hours are all other times except certain holidays."

Does "12:00 AM" mean 12 noon or 12 midnight?

I wondered why they didn't say that weekend hours would be from Friday 9:00
PM through Monday 5:59 AM.

This company apparently has plans for just weekend minutes or night and
weekend minutes. The one they were promoting included both night and
weekend minutes.

I am hoping they don't charge me with daytime minutes if I use the phone
after midnight Sunday, that is, Monday from 12:00:01 (I'm trying to say a
second after midnight) through 5:59 AM on Monday mornings.

If there is a standard definition in the entire telecom industry, then
maybe they don't think they should have to explain this in deep detail in
their brochures.

If they are going by the way digital watches display the "p" for PM, then
I'll have to double-check to see if my various clocks and watches are
consistent.

I liked the number of minutes this company offers (more than the hightly
advertised company is offering right now) and the option to have coverage
over the whole country so I can avoid "roaming" charges in the USA. I had
to give up some daytime minutes to do this, but that gives me more night
and weekend minutes as the overall total is the same. The cost of "excess"
daytime minutes is much less than the cost of roaming minutes would be if I
opted for the "local" plan or the "regional" plan.

I hope I'm not being overly paranoid when I think maybe there is a catch in
the way they describe their times for weekend minutes and night minutes.

Thanks for any comments!


--
Gail from Ohio USA
--
The Telecom Digest is currently mostly robomoderated. Please mail
messages to edi...@telecom-digest.org.

The Old Bear

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Dec 22, 2001, 1:21:02 AM12/22/01
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"Gail M. Hall" <gmh...@apk.net> writes:

>From: "Gail M. Hall" <gmh...@apk.net>
>Newsgroups: comp.dcom.telecom
>Subject: Need clarification of terms for noon and midnight using PM and AM
>Date: 21 Dec 2001 23:34:37 -0500
>
>This is really telecom related because I'm looking at what kind of usage
>"minutes" are called what and when.
>
>Is there a consistent definition of 12:00 AM and 12:00 PM in the telecom
>business?
>
>Technically there is no such thing as 12:00 AM or PM. There is 12:00 noon
>and 12:00 midnight. AM means before noon and PM means after noon, but
>right at noon, it is straight-up noon.

The convention is that 12:00AM is midnight and 12:00PM is noon. As you
note, it's technically wrong because the meridians of noon and midnight
are neither AM nor PM. However, logic has it that one minute after
midnight is 12:01AM and therefore midnight is 12:00AM. Same logic applies
to noon being 12:00PM because one minute later is 12:01PM.

While confusing, this is less confusing that the alternative of calling
noon 12:00AM and the rest of the hour 12:01PM to 12:59PM. Aaaaargh.

>It seems to me that it would be more clear if in the text defining times
>the 24-hour format could be used, just as weight is expressed in metric and
>US measures.

Then one needs to determine whether the stroke of midnight is 24:00 hours
today or 0:00 hours tomorrow. :)

>Here is a quote of the definition of night and weekend hours in a brochure
>that I got.
>
> Night hours are 9:00 PM - 5:59 AM, Monday - Friday.
> Weekend hours are 12:00 AM Saturday - 11:59 PM Sunday.
> Peak hours are all other times except certain holidays.
>
>Does "12:00 AM" mean 12 noon or 12 midnight?

No one ever said that MBAs and marketing people know how to write clearly.

> . . .


>
>I hope I'm not being overly paranoid when I think maybe there is a catch
>in the way they describe their times for weekend minutes and night minutes.

No, you're not being overly paranoid. In the telecom industry, the
"gotcha" is the rule rather than the exception. Pricing plans are designed
specifically to be confusing and to make comparisons between carriers all
but impossible. This is known as free market competition.

You can ask for clarification -- but your sales person may be equally
confused and dispense the wrong answer. You're best bet is to ask to see
a typical itemized billing statement to see how calls at various times
are noted (day, evening, weekend).

I wish you well.

Cheers,
The Old Bear

Mark Brader

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Dec 22, 2001, 1:47:10 AM12/22/01
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>> It seems to me that it would be more clear if in the text defining times
>> the 24-hour format could be used ...


> Then one needs to determine whether the stroke of midnight is 24:00 hours
> today or 0:00 hours tomorrow. :)

According to the relevant international standard, ISO 8601, it is both.
--
Mark Brader, Toronto | "[That] statement is so full of hubris
m...@vex.net | you can hear the wax melting." -- Steve Summit

Mark Crispin

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Dec 22, 2001, 2:06:59 AM12/22/01
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On 21 Dec 2001, Gail M. Hall wrote:
> Is there a consistent definition of 12:00 AM and 12:00 PM in the telecom
> business?
> Technically there is no such thing as 12:00 AM or PM. There is 12:00 noon
> and 12:00 midnight. AM means before noon and PM means after noon, but
> right at noon, it is straight-up noon.

I think that you answered your own question. There is no definition.

However, when "12:00 AM" and "12:00 PM" are (mis)used, "12:00 AM" almost
always refers to midnight and "12:00 PM" almost always refers to noon. I
have never seen or heard the terms used otherwise; however that doesn't
mean anything since I have not exhaustive tested every device or quizzed
every human being in the world. But there definitely is a convention.

Given that there is just a convention and no definition, the only rational
approach is to tenatively assume based upon the convention, and then to
get a verification of that assumption before acting on it.

> "Night hours are 9:00 PM - 5:59 AM, Monday - Friday.
> Weekend hours are 12:00 AM Saturday - 11:59 PM Sunday.
> Peak hours are all other times except certain holidays."
>
> Does "12:00 AM" mean 12 noon or 12 midnight?

"12:00 AM" almost certainly refers to midnight here.

I have observed that some people are confused by "midnight Saturday", and
think that it means "midnight Saturday night" (another improper term) and
hence "midnight between Saturday and Sunday". Such individuals strangely
find "12:00 AM Saturday" to be easier to comprehend.

Of course, "midnight Saturday morning" is unambiguous.

> I wondered why they didn't say that weekend hours would be from Friday 9:00
> PM through Monday 5:59 AM.

As far as I can tell -- you should request a clarification *in writing* --
what was intended is:

"Night hours are midnight - 5:59 AM and 9:00 PM - 11:59 PM, Monday - Friday.
Weekend hours are midnight Saturday morning - 11:59 PM Sunday.


Peak hours are all other times except certain holidays.

All times are inclusive."

Not only does that fit with the convention, but it makes the most sense.
But I still wouldn't make any calls until I got a verification.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.

Justa Lurker

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Dec 22, 2001, 2:09:33 AM12/22/01
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It was 21 Dec 2001 23:34:37 -0500, and
"Gail M. Hall" <gmh...@apk.net> wrote in comp.dcom.telecom:

| Is there a consistent definition of 12:00 AM and 12:00 PM
| in the telecom business?

12:01 AM is one minute past 12:00 AM, commonly called midnight.
12:01 PM is one minute past 12:00 PM, commonly called noon.

| "Night hours are 9:00 PM - 5:59 AM, Monday - Friday.
| Weekend hours are 12:00 AM Saturday - 11:59 PM Sunday.
| Peak hours are all other times except certain holidays."
|
| Does "12:00 AM" mean 12 noon or 12 midnight?

Midnight.

| I wondered why they didn't say that weekend hours would
| be from Friday 9:00 PM through Monday 5:59 AM.

Because they are not in all cases. When I had a weekend
rate package they did allow Friday Night and Monday Morning
as weekend. Kind of odd to start at midnight anyways.

| This company apparently has plans for just weekend minutes
| or night and weekend minutes. The one they were promoting
| included both night and weekend minutes.

The company I am thinking of has a national package that is
weekend only on the 'bonus' minutes. Night and Weekend is
offered on regional and local plans only.

| I am hoping they don't charge me with daytime minutes if I
| use the phone after midnight Sunday, that is, Monday from
| 12:00:01 (I'm trying to say a second after midnight) through
| 5:59 AM on Monday mornings.

They won't on a 'night and weekend' plan. But if your plan only
includes weekend minutes and the definitions at the top are given
expect to be billed at regular rates at 12:01 AM Monday morning.

JL

Craig Macbride

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Dec 22, 2001, 6:56:06 AM12/22/01
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old...@arctos.com (The Old Bear) writes:

>However, logic has it that one minute after
>midnight is 12:01AM and therefore midnight is 12:00AM.

It doesn't even need to be one minute. Midnight is an infinitely small
period. One second after midnight is 12:00:01am.

>While confusing, this is less confusing that the alternative of calling
>noon 12:00AM and the rest of the hour 12:01PM to 12:59PM. Aaaaargh.

Or having one second past 12:00:00am called 12:00:01pm!


--
Craig Macbride <cra...@ragingbull.com> http://www.nyx.net/~cmacbrid
---------------------------------------------------------------------------
"People want to be educated, they shouldn't be
watching television, they should be reading books." - Jerry Springer

Jay R. Ashworth

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Dec 22, 2001, 10:55:23 AM12/22/01
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Last night, on Capitol Beat, The Old Bear <old...@arctos.com> said:
> >From: "Gail M. Hall" <gmh...@apk.net>
> >Is there a consistent definition of 12:00 AM and 12:00 PM in the telecom
> >business?
>
> The convention is that 12:00AM is midnight and 12:00PM is noon. As you
> note, it's technically wrong because the meridians of noon and midnight
> are neither AM nor PM. However, logic has it that one minute after
> midnight is 12:01AM and therefore midnight is 12:00AM. Same logic applies
> to noon being 12:00PM because one minute later is 12:01PM.
>
> While confusing, this is less confusing that the alternative of calling
> noon 12:00AM and the rest of the hour 12:01PM to 12:59PM. Aaaaargh.

Concur; he's right.

On both counts.

0000 is 12 ayem, 1200 is 12 peyem.

2400 is also 235960 (or 61, on leapsecond days) and is the midnight at
the end of a day.

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Jay R. Ashworth

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Dec 22, 2001, 10:56:46 AM12/22/01
to
Last night, on Capitol Beat, Mark Brader <m...@vex.net> said:
> According to the relevant international standard, ISO 8601, it is both.

Thanks for the ref, Mark. I Got Lucky with google.

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Jay R. Ashworth

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Dec 22, 2001, 10:59:47 AM12/22/01
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Last night, on Capitol Beat, Mark Crispin <m...@CAC.Washington.EDU> said:
> As far as I can tell -- you should request a clarification *in writing* --
> what was intended is:
>
> "Night hours are midnight - 5:59 AM and 9:00 PM - 11:59 PM, Monday - Friday.
> Weekend hours are midnight Saturday morning - 11:59 PM Sunday.
> Peak hours are all other times except certain holidays.
> All times are inclusive."
>
> Not only does that fit with the convention, but it makes the most sense.
> But I still wouldn't make any calls until I got a verification.

*I*, personally, would have written it "Peak hour rates will be charged
for the minutes of any call which fall between 6am and 8:59pm, Monday
through Friday; all other call minutes are off-peak.", which is what
most carriers actually seem to do these days.

Cept Nextel, who still start at 2000. :-)

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Mark Brader

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Dec 22, 2001, 1:12:28 PM12/22/01
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Jay Ashworth writes:
> 2400 is also 235960 (or 61, on leapsecond days) and is the midnight at
> the end of a day.

You can write that if you want, but it doesn't conform to ISO 8601.
Under the standard, midnight is 00:00:00 or 24:00:00, but not 23:60:00
or 23:59:60. 23:59:60 is possible only due to a leap second (and then,
of course, only if your time zone is UTC; where *I* live, they occur
at 18:59:60 EST [winter, zone -5] or 19:59:60 EDT [summer, zone -4]);
and 23:59:61 is impossible.
--
Mark Brader, Toronto | "It is one thing to praise discipline, and another
m...@vex.net | to submit to it." -- Miguel de Cervantes, 1613

My text in this article is in the public domain.

Dr. Joel M. Hoffman

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Dec 22, 2001, 1:27:05 PM12/22/01
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>> The convention is that 12:00AM is midnight and 12:00PM is noon. As you
>> note, it's technically wrong because the meridians of noon and midnight
>> are neither AM nor PM. However, logic has it that one minute after
>> midnight is 12:01AM and therefore midnight is 12:00AM. Same logic applies
>> to noon being 12:00PM because one minute later is 12:01PM.
>>
>> While confusing, this is less confusing that the alternative of calling
>> noon 12:00AM and the rest of the hour 12:01PM to 12:59PM. Aaaaargh.

The only confusing part (with reality --- because this is the scheme
everyone uses) is that an hour after 10am is 11am but an hour after
11am is 12pm.

Steven J. Sobol

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Dec 22, 2001, 1:38:45 PM12/22/01
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From 'Gail M. Hall' <gmh...@apk.net>:

>This is really telecom related because I'm looking at what kind of usage
>"minutes" are called what and when.

The question is, how important is this definition? Cellular night and
weekend minutes SPAN noons and midnights. Are you concerned about
timing on a long-distance plan?

--
JustThe.net LLC - Steve "Web Dude" Sobol, CTO ICQ: 56972932/WebDude216
website: http://JustThe.net email: sjs...@JustThe.net phone: 216.619.2NET
postal: 5686 Davis Drive, Mentor On The Lake, OH 44060-2752 DalNet: ZX-2

David W. Tamkin

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Dec 22, 2001, 6:38:09 PM12/22/01
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Mark Crispin <m...@CAC.Washington.EDU> wrote in
<Pine.NXT.4.50.01122...@Tomobiki-Cho.CAC.Washington.EDU>:

| However, ... "12:00 AM" almost


| always refers to midnight and "12:00 PM" almost always refers to noon. I

| have never seen or heard the terms used otherwise; ...

I have seen them used the other way quite often and quite adamantly. There
simply are people who consider noon part of the morning and midnight part of
the evening and are wrapped up in their own worlds, deaf to convention.

There was a court case a couple decades back where a motorist parked in the
late afternoon in an area marked "No Parking 10 AM - 12 PM." The ticketing
police officer insisted that "12 PM" meant midnight. The judge declared that
12 PM was midnight, that there was no such time as 12 AM, and that the ticket
was valid. An appellate court, whose judges had grown up with their ears
open, overturned the verdict.

Brett Frankenberger

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Dec 22, 2001, 8:19:40 PM12/22/01
to

The Old Bear <old...@arctos.com> wrote:
>
>The convention is that 12:00AM is midnight and 12:00PM is noon. As you
>note, it's technically wrong because the meridians of noon and midnight
>are neither AM nor PM. However, logic has it that one minute after
>midnight is 12:01AM

As is one second after midnight, or one nanosecond after midnight, or
1*10^-100 seconds after midnight, or ...

>and therefore midnight is 12:00AM. Same logic applies
>to noon being 12:00PM because one minute later is 12:01PM.
>
>While confusing, this is less confusing that the alternative of calling
>noon 12:00AM and the rest of the hour 12:01PM to 12:59PM. Aaaaargh.

Especially since many, many times are commonly written as 12:00 (such
as 12:00:01, for example), but only 12:00:00.0000000... is really in
the realm of "neither AM nor PM".

-- Brett

The Old Bear

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Dec 22, 2001, 9:53:22 PM12/22/01
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r...@rbfnet.com (Brett Frankenberger) writes:

>From: r...@rbfnet.com (Brett Frankenberger)
>Newsgroups: comp.dcom.telecom
>Subject: Re: Need clarification of terms for noon and midnight using PM and AM
>Date: 22 Dec 2001 20:19:40 -0500
>
>The Old Bear <old...@arctos.com> wrote:
>>
>>The convention is that 12:00AM is midnight and 12:00PM is noon. As you
>>note, it's technically wrong because the meridians of noon and midnight
>>are neither AM nor PM. However, logic has it that one minute after
>>midnight is 12:01AM
>
>As is one second after midnight, or one nanosecond after midnight, or
>1*10^-100 seconds after midnight, or ...
>
>>and therefore midnight is 12:00AM. Same logic applies
>>to noon being 12:00PM because one minute later is 12:01PM.
>>
>>While confusing, this is less confusing that the alternative of calling
>>noon 12:00AM and the rest of the hour 12:01PM to 12:59PM. Aaaaargh.
>
>Especially since many, many times are commonly written as 12:00 (such
>as 12:00:01, for example), but only 12:00:00.0000000... is really in
>the realm of "neither AM nor PM".

Brett:

You're correct -- however I was using the example of 12:01 because it
is easier for the average person to grasp and to remember.

Along the same line, I recall the campus radio station at the college
I attended (a well-known science and engineering school and recognised
nerd haven) used to do special programming on the morning when Daylight
Savings Time ended.

The in-joke was that the hands of the clock would approach 2:00AM
asymtotically, and at some infititesimal delta interval before 2:00AM
local time, it would become 1:00AM local time. This, of course,
was a point discontinuity in time and worthy of intense scientific
study -- at least by the campus radio station. :)

Cheers,
The Old Bear

Gail M. Hall

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Dec 23, 2001, 12:27:02 AM12/23/01
to
Thanks to all who commented on my question about which 12:00 AM or PM is
midnight and which is noon.

The plan I ended up with is a national plan with the night and weekend
option.

That means I can call from anywhere in the US without paying roaming fees.
The downside is that fewer peak hour minutes are allowed with this plan. A
minute of roaming, though, was shown as 60 cents per minutes, whereas
paying for minutes over your allowance is only 40 cents per minute. a 20
cents per minute difference can mean a lot if you have to be on the phone
for 10 minutes, even more if you have to be on the phone longer.

If you want to get lots more minutes, then the charge for excess over the
allowance goes down to 35 cents a minute. This was supposed to be a
special offer, so I don't know how long it will last.

Thanks again to all who commented on this question.


--
Gail from Ohio USA

Jay R. Ashworth

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Dec 23, 2001, 2:22:51 PM12/23/01
to
Last night, on Capitol Beat, Mark Brader <m...@vex.net> said:
> Jay Ashworth writes:
> > 2400 is also 235960 (or 61, on leapsecond days) and is the midnight at
> > the end of a day.
>
> You can write that if you want, but it doesn't conform to ISO 8601.
> Under the standard, midnight is 00:00:00 or 24:00:00, but not 23:60:00
> or 23:59:60. 23:59:60 is possible only due to a leap second (and then,
> of course, only if your time zone is UTC; where *I* live, they occur
> at 18:59:60 EST [winter, zone -5] or 19:59:60 EDT [summer, zone -4]);
> and 23:59:61 is impossible.

I went off and read a bit, and I see that you're right, 235960 !=
240000. Hmmm... don't I recall, though, that there *has* been at least
one double-leap second, or at least that they were planning for it?

ADO's TZ archive is pretty cool, BTW.

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Jay R. Ashworth

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Dec 23, 2001, 2:23:53 PM12/23/01
to
Last night, on Capitol Beat, The Old Bear <old...@arctos.com> said:
> The in-joke was that the hands of the clock would approach 2:00AM
> asymtotically, and at some infititesimal delta interval before 2:00AM
> local time, it would become 1:00AM local time. This, of course,
> was a point discontinuity in time and worthy of intense scientific
> study -- at least by the campus radio station. :)

And the antidote to that in-joke is, of course, that 1:59:59 AM is not
followed by 1:00:00 AM.

"1:59:59AM EST" is followed by "1:00:00AM EDT".

The time zone is required to be part of the timestamp.

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Jay R. Ashworth

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Dec 23, 2001, 2:26:28 PM12/23/01
to
Last night, on Capitol Beat, Gail M. Hall <gmh...@apk.net> said:
> The plan I ended up with is a national plan with the night and weekend
> option.
>
> That means I can call from anywhere in the US without paying roaming fees.
> The downside is that fewer peak hour minutes are allowed with this plan. A
> minute of roaming, though, was shown as 60 cents per minutes, whereas
> paying for minutes over your allowance is only 40 cents per minute. a 20
> cents per minute difference can mean a lot if you have to be on the phone
> for 10 minutes, even more if you have to be on the phone longer.

FWIW, .40/min overtime is fairly pricey these days.

That's, on average, 4 times what you're probably paying for your base
weekday minutes, which seem to average .10/min from just about
everyone. If you go over at *all* the first month, adjust upwards.

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

David W. Tamkin

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Dec 23, 2001, 2:49:26 PM12/23/01
to

| I went off and read a bit, and I see that you're right, 235960 !=
| 240000. Hmmm... don't I recall, though, that there *has* been at least
| one double-leap second, or at least that they were planning for it?

There never has been a double leap second (though I can't say whether there's
an allowance for one). However, ISTR that in 1972 one leap second was added
on June 30 (July 1 in zones ahead of UTC) and another on December 31
(January, 1, 1973 in zones ahead of UTC). I happened to have started 1972
on EST and finished it on CST, so I call it the longest year of my life (366
days, one hour, and two seconds).

[My personal leap second story: on December 31, 1989, a local news radio
station carried the news of that day's leap second and kept proclaiming
that "1989 will be one second longer than 1988." It was a Sunday and their
offices were closed, so I called their emergency hotline for telling them
about breaking news and reminded them that 1988 had had a leap DAY. They
then changed it to something like "today will be one second longer than
yesterday."]

In another article Jay said,

> "1:59:59AM EST" is followed by "1:00:00AM EDT".

No, 1:59:59 AM EDT is followed by 1:00:00 AM EST the day the clocks are
set back; 1:59:59 AM EST is followed by 3:00:00 AM EDT the day they're set
ahead.

Al Gillis

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Dec 23, 2001, 5:20:36 PM12/23/01
to
Ok, after numerous long technical disertations on the topic of AM vs PM and
when one gives way to the other we've finally got that problem resolved.

Now, here's one for us to concentrate on over the upcoming holiday: How
many Angels can dance on the head of a pin?

As these Angels are most likely Christian Angels I'll add "Merry Christmas
to all comp.dcom.telecom folks!" (Note to adherents of other belief
systems: select the deity support staff member of your choice when pondering
the question above!)

Al

Mark Brader

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Dec 23, 2001, 8:08:01 PM12/23/01
to
Jay Ashworth:

> Hmmm... don't I recall, though, that there *has* been at least
> one double-leap second, or at least that they were planning for it?

If Jay is a C programmer, he may be thinking of section 4.12.1 of the
original ANSI C standard -- which became section 7.12.1 in the first
ISO version -- where it says that the "normal range" of the tm_second
member of a broken-down time is 0 to 61, thus allowing "for as many
as two leap seconds."

I'm afraid it was me who suggested to X3J11 that they needed to allow
for that. I didn't understand the rules for leap seconds fully then
and, evidently, neither did they. I believe it's been corrected in
the new standard.
--
Mark Brader Summary of issue: Fix FORTRAN-8x.
Toronto Committee Response: This proposal contains
m...@vex.net insurmountable technical errors.
-- X3J11 responses to 2nd public review

My text in this article is in the public domain.

Jay R. Ashworth

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Dec 24, 2001, 12:38:33 AM12/24/01
to
Last night, on Capitol Beat, David W. Tamkin <nob...@rutgers.rutgers.edu> said:
> j...@baylink.com wrote in <slrna2cbc...@dorothy.baylink.com>:
> | I went off and read a bit, and I see that you're right, 235960 !=
> | 240000. Hmmm... don't I recall, though, that there *has* been at least
> | one double-leap second, or at least that they were planning for it?
>
> There never has been a double leap second (though I can't say whether there's
> an allowance for one). However, ISTR that in 1972 one leap second was added
> on June 30 (July 1 in zones ahead of UTC) and another on December 31
> (January, 1, 1973 in zones ahead of UTC). I happened to have started 1972
> on EST and finished it on CST, so I call it the longest year of my life (366
> days, one hour, and two seconds).

<chuckle>

> [My personal leap second story: on December 31, 1989, a local news radio
> station carried the news of that day's leap second and kept proclaiming
> that "1989 will be one second longer than 1988." It was a Sunday and their
> offices were closed, so I called their emergency hotline for telling them
> about breaking news and reminded them that 1988 had had a leap DAY. They
> then changed it to something like "today will be one second longer than
> yesterday."]

<giggle>

> In another article Jay said,
>
> > "1:59:59AM EST" is followed by "1:00:00AM EDT".
>
> No, 1:59:59 AM EDT is followed by 1:00:00 AM EST the day the clocks are
> set back; 1:59:59 AM EST is followed by 3:00:00 AM EDT the day they're set
> ahead.

Eek. Oops. Thanks.

I wonder what the time libraries do if you present them with 02:30:00
EDT on the first day of EDT. :-)

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Jay R. Ashworth

unread,
Dec 24, 2001, 12:40:00 AM12/24/01
to
Last night, on Capitol Beat, Mark Brader <m...@vex.net> said:
> Jay Ashworth:
> > Hmmm... don't I recall, though, that there *has* been at least
> > one double-leap second, or at least that they were planning for it?
>
> If Jay is a C programmer, he may be thinking of section 4.12.1 of the
> original ANSI C standard -- which became section 7.12.1 in the first
> ISO version -- where it says that the "normal range" of the tm_second
> member of a broken-down time is 0 to 61, thus allowing "for as many
> as two leap seconds."
>
> I'm afraid it was me who suggested to X3J11 that they needed to allow
> for that. I didn't understand the rules for leap seconds fully then
> and, evidently, neither did they. I believe it's been corrected in
> the new standard.

That might well be where I got it, if it was in K&&R2 or the Tartan
guy's book. Or maybe I even got it from the header files.

So, then, there isn't any way at all that we can actually *have* a
second 61 in any currently in use timescale?

Cheers,
-- jra
--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Robert Casey

unread,
Dec 24, 2001, 7:58:58 PM12/24/01
to
My car insurance would say things like "Coverage starts on
(whatever day) at 12:01 AM, to avoid this confusion.

Alan Fowler

unread,
Dec 25, 2001, 4:47:57 AM12/25/01
to
"Al Gillis" <a...@aracnet.com> wrote:

>Ok, after numerous long technical disertations on the topic of AM vs PM and
>when one gives way to the other we've finally got that problem resolved.
>
>Now, here's one for us to concentrate on over the upcoming holiday: How
>many Angels can dance on the head of a pin?

None. Angels are too busy good works to have time
for frivolities.

Alan.

Wesrock

unread,
Dec 25, 2001, 9:28:44 AM12/25/01
to
Robert Casey wa2...@ix.netcom.com wrpte at 12/24/01 6:58 PM Central Standard
Time

>My car insurance would say things like "Coverage starts on
>(whatever day) at 12:01 AM, to avoid this confusion.

I just read in a railroad newsletter to employees that the Kansas City
Southern Railroad would not accept freight trains from the BNSF Railroad at
Alliance, Texas, from 12:01 a.m. December 24 to 11:59 p.m. December 25.

It seems to me I read somewhere that railroad rules forbid using 12:00
noon or 12:00 midnight (however designated) for any purpose.

They prefer not to have train wrecks.

David Lesher

unread,
Dec 25, 2001, 10:44:00 AM12/25/01
to
Robert Casey <wa2...@ix.netcom.com> writes:

>My car insurance would say things like "Coverage starts on
>(whatever day) at 12:01 AM, to avoid this confusion.

As do most airline schedules, etc.

--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

danny burstein

unread,
Dec 25, 2001, 12:24:57 PM12/25/01
to
In <a0a6ro$3ql$1...@panix1.panix.com> wb8...@panix.com (David Lesher) writes:

>Robert Casey <wa2...@ix.netcom.com> writes:

>>My car insurance would say things like "Coverage starts on
>>(whatever day) at 12:01 AM, to avoid this confusion.

>As do most airline schedules, etc.

And the switchovers between "standard" and "daylight savings" time are
scheduled for 02:00 in part to avoid any confusion.
--
_____________________________________________________
Knowledge may be power, but communications is the key
dan...@panix.com
[to foil spammers, my address has been double rot-13 encoded]

Chris Jones

unread,
Dec 25, 2001, 8:08:15 PM12/25/01
to
"Gail M. Hall" <gmh...@apk.net> writes:

> This is really telecom related because I'm looking at what kind of usage
> "minutes" are called what and when.
>

> Is there a consistent definition of 12:00 AM and 12:00 PM in the telecom
> business?
>

> Technically there is no such thing as 12:00 AM or PM. There is 12:00 noon
> and 12:00 midnight. AM means before noon and PM means after noon, but
> right at noon, it is straight-up noon.

I recall reading once, a long time ago, that since AM means "ante meridian" and
PM means "post meridian" and ante and post mean before and after, respectively,
that noon was written 12 M since it was the "meridian" the other times were
before or after. Nobody does this that I recall (or it's certainly obscure if
anyone does). What would you write for midnight, in any case? And in English,
probably most people would think that 12 M meant midnight.

Al Gillis

unread,
Dec 26, 2001, 12:21:28 AM12/26/01
to
I'm pretty certain that Chris is right about the ante meridian, post
meridian and the possibly archaic usage "12 M".

I wonder how much the American railroad (or is it railway?) contributed to
this time issue? For some time I've believed that the railroads pushed the
widespread use of the "time zone" concept (not necessarily the development
of time zones but their common use), removing from each town along the
tracks its' own time standard (based on sidereal "noon") and replacing it
with "Railroad Time". I'm wondering why the railroads didn't adopt a 24
hour timekeeping system to avoid the obvious problems we're now chewing on.
If they'd used a 24 hour system 100 years ago think of all the bandwidth
we'd save now by not doing all this keyboarding! So anyone have some
references to these questions or other ideas or opinions?

To drag this topic back into the Telecomm realm, how do Telecom companies do
timekeeping today? Some years ago AT&T used the US Central Time as their
"Network Time". I don't know how or if they synched to National Bureau of
Standards (now NIST - National Institute of Standards and Technology) for
precise time of day information. I believe they generated their own time
interval standards at Hillsborough, MO which clocked their network (and
where we now derive the terms Stratum 1, Stratum 2, etc. terms for stability
and interval accuracy). Maybe this means a trip to the local repository of
Bell System Technical Journals to kill a wintery afternoon!

Merry Christmas to one and all !!

Al


Chris Jones <c...@TheWorld.com> wrote in message
news:tdn666u...@shell01.TheWorld.com...

Jay R. Ashworth

unread,
Dec 26, 2001, 1:54:39 AM12/26/01
to
Last night, on Capitol Beat, Chris Jones <c...@TheWorld.com> said:
> I recall reading once, a long time ago, that since AM means "ante
> meridian" and PM means "post meridian" and ante and post mean before
> and after, respectively, that noon was written 12 M since it was
> the "meridian" the other times were before or after. Nobody does
> this that I recall (or it's certainly obscure if anyone does). What
> would you write for midnight, in any case? And in English, probably
> most people would think that 12 M meant midnight.

You did read that; it's correct; and no one does it, for precisely the
reason you intuit. :-)

Cheers,
-- jr '0000...1200' a


--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

Jay R. Ashworth

unread,
Dec 26, 2001, 2:03:03 AM12/26/01
to
Last night, on Capitol Beat, Al Gillis <a...@aracnet.com> said:
> I wonder how much the American railroad (or is it railway?) contributed to
> this time issue? For some time I've believed that the railroads pushed the
> widespread use of the "time zone" concept (not necessarily the development
> of time zones but their common use), removing from each town along the
> tracks its' own time standard (based on sidereal "noon") and replacing it
> with "Railroad Time". I'm wondering why the railroads didn't adopt a 24
> hour timekeeping system to avoid the obvious problems we're now chewing on.
> If they'd used a 24 hour system 100 years ago think of all the bandwidth
> we'd save now by not doing all this keyboarding! So anyone have some
> references to these questions or other ideas or opinions?

Yes, indeed, timezones were originated by the rail industry. Today,
the laws implementing the boundaries are promulgated, if memory serves
me correctly, by the Department of Commerce.

> To drag this topic back into the Telecomm realm, how do Telecom companies do
> timekeeping today? Some years ago AT&T used the US Central Time as their
> "Network Time". I don't know how or if they synched to National Bureau of
> Standards (now NIST - National Institute of Standards and Technology) for
> precise time of day information. I believe they generated their own time
> interval standards at Hillsborough, MO which clocked their network (and
> where we now derive the terms Stratum 1, Stratum 2, etc. terms for stability
> and interval accuracy). Maybe this means a trip to the local repository of
> Bell System Technical Journals to kill a wintery afternoon!

Yeah, that'd be a good start. AT&T's original Strat-1 cluster was
indeed, Google tells me, in Hillsboro, MO. Back in the bad old days,
the circuits distributed the timing, or so I understand it -- I'm
*still* looking for a used SR-2275 :-) -- but nowadays, especially in
this age of multiple IXC's, and smarter gear -- I gather that stuff is
merely re-framed to fit the local clock.

It used to be, too, that the single most accurate reference signal
available to the general public was the 3.579545...MHz color subcarrier
oscillator in a TV set *watching a network originated program*.

That, of course, died when frame-synchronizers became practical, and
became immaterial when GPS receivers got cheap enough -- they being how
standard time is moved around quite a bit these days.

Google for, among other things "NTP", if you'd like to learn more about
computerized time than you ever really wanted to know. :-)

Cheers,
-- jra


--
Jay R. Ashworth j...@baylink.com
Member of the Technical Staff Baylink
The Suncoast Freenet The Things I Think
Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274

Fanfic: it's enough to make you loose your mind.
-- me

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