Local Time NTP Server

[Beth Connell]

Hi,
I'm struggling to find any information on where the free NTP servers are geographically based. In particular, I'm wondering where Facebook, Google, Microsoft, etc are based within the UK. Just for curiousity, I'm wondering how this affects any interference to my location.

Thanks

[Jakob Bohm]

All NTP time is GMT (now named UTC, after HM government dropped the
ball). The only geographic factor is the "ping time" to the time
server, the servers that are the most distant (longest ping) are the
GPS and Galileo satellites, that are hundreds or thousands of km from
the receiver, and use their own (non-NTP) protocols to correct for the
delay.

Another problem is if the NTP server is one of those that deliberately
return slightly wrong time before and after each leap second to "smooth
out" the leap, some of the companies you mention reportedly do that.


Enjoy

Jakob
--
Jakob Bohm, CIO, Partner, WiseMo A/S. https://www.wisemo.com
Transformervej 29, 2860 Søborg, Denmark. Direct +45 31 13 16 10
This public discussion message is non-binding and may contain errors.
WiseMo - Remote Service Management for PCs, Phones and Embedded

[William Unruh]

On 2020-08-24, Beth Connell <beth.c...@hoptroff.com> wrote:
> Hi,
> I'm struggling to find any information on where the free NTP servers are geographically based. In particular, I'm wondering where Facebook, Google, Microsoft, etc are based within the UK. Just for curiousity, I'm wondering how this affects any interference to my location.

All are based all over the place.
No idea what "interference" you are talking about, but I cannot think of
any definition of that word which would make your last sentance make
sense especially with respect to ntp.
iPerhaps if you told us what you are seeing as a problem with your ntp
use, and then people could perhaps suggest ways of solving that problem.

[William Unruh]

On 2020-08-24, Jakob Bohm <jb-u...@wisemo.com.invalid> wrote:
> On 2020-08-24 12:51, Beth Connell wrote:
>> Hi,
>> I'm struggling to find any information on where the free NTP servers are geographically based. In particular, I'm wondering where Facebook, Google, Microsoft, etc are based within the UK. Just for curiousity, I'm wondering how this affects any interference to my location.
>>
>> Thanks
>>
>
> All NTP time is GMT (now named UTC, after HM government dropped the
> ball). The only geographic factor is the "ping time" to the time
> server, the servers that are the most distant (longest ping) are the
> GPS and Galileo satellites, that are hundreds or thousands of km from
> the receiver, and use their own (non-NTP) protocols to correct for the
> delay.

It was renamed because UTC has nothing to do with Greenwich. For
historical reasons, the time at Greenwich is the same as UTC.
(Note that the prime meridian now runs through a garbage can in a park
just south of the Thames rive in London and not along the line marked
on the ground in Greenwich. No idea why you believe the govt dropped the
ball. Because the location of Greenwich moves (plate techtonics) it
would introduce inaccuracies into the definition of time if it were tied
to Greenwich. Also, you cannot ping the sattelites.

[Jakob Bohm]

On 2020-08-24 16:07, William Unruh wrote:
> On 2020-08-24, Jakob Bohm <jb-u...@wisemo.com.invalid> wrote:
>> On 2020-08-24 12:51, Beth Connell wrote:
>>> Hi,
>>> I'm struggling to find any information on where the free NTP servers are geographically based. In particular, I'm wondering where Facebook, Google, Microsoft, etc are based within the UK. Just for curiousity, I'm wondering how this affects any interference to my location.
>>>
>>> Thanks
>>>
>>
>> All NTP time is GMT (now named UTC, after HM government dropped the
>> ball). The only geographic factor is the "ping time" to the time
>> server, the servers that are the most distant (longest ping) are the
>> GPS and Galileo satellites, that are hundreds or thousands of km from
>> the receiver, and use their own (non-NTP) protocols to correct for the
>> delay.
>
> It was renamed because UTC has nothing to do with Greenwich. For
> historical reasons, the time at Greenwich is the same as UTC.
> (Note that the prime meridian now runs through a garbage can in a park
> just south of the Thames rive in London and not along the line marked
> on the ground in Greenwich. No idea why you believe the govt dropped the
> ball. Because the location of Greenwich moves (plate techtonics) it
> would introduce inaccuracies into the definition of time if it were tied
> to Greenwich. Also, you cannot ping the sattelites.

I used "ping time" as the popular name of the round trip time (as
actually measured by NTP implementations), and thus as a somewhat
vague reference to the equivalant satellite-to-ground time delay.

As for the reference to HM Government, there was a rumor, many years
ago, that the budgets cuts caused the relevant time management job to
revert to the IERS in Paris, thus loosing Britain the honor of having
the time standard refer to the British victory at the Meridian
conference.

If the Greenwich observatory had still been in full operation, the
scientists running it would probably have applied the necessary
corrections for the ground shifting under their instruments,
rather than having the hole place demolished in favor of a symbolic
line on the ground. They would also probably have become the time
setting command center for the Galileo satellites that replaced their
daily dropping of an actual ball to signal exact meridian noon to
ships setting their navigation chronometers.

>>
>> Another problem is if the NTP server is one of those that deliberately
>> return slightly wrong time before and after each leap second to "smooth
>> out" the leap, some of the companies you mention reportedly do that.
>>
>>
>> Enjoy
>>
>> Jakob

[William Unruh]

Is Britain really so bereft of self confidence and feelings of self
worth that they have to hang onto symbols of their past (over 100 year
old) glories? Time is universal, owned by the world.

>
> If the Greenwich observatory had still been in full operation, the
> scientists running it would probably have applied the necessary
> corrections for the ground shifting under their instruments,

You simply cannot have a standard which drifts around. You need it to be
fixed, eg to the stars.

> rather than having the hole place demolished in favor of a symbolic
> line on the ground. They would also probably have become the time
> setting command center for the Galileo satellites that replaced their
> daily dropping of an actual ball to signal exact meridian noon to
> ships setting their navigation chronometers.

Again, that daily dropping went outi (as a useful device) almost a hundred years ago, once
radio was invented. (In Canada CBC still broadcasts "At the beginning of
the long dash, the time is exactly 10 oclock Pacific Daylight time"-- I,
just 37 min ago, heard it. I assume BBC has the equivalent.)
That was a lot more accurate than the one second at best reaction time
to the ball dropping. And even GPS with the 10m fuzzing was over a
million times more accurate. And its lattitude is probably a million
times more accurate than chronometric lattitude. Is there anyone on a
ship these days that still knows how to use a sextant?

>
>
>
>>>
>>> Another problem is if the NTP server is one of those that deliberately
>>> return slightly wrong time before and after each leap second to "smooth
>>> out" the leap, some of the companies you mention reportedly do that.

I agree that that "solution" is pretty horrible.

>>>
>>>
>>> Enjoy
>>>
>>> Jakob
>
>
> Enjoy
>
> Jakob

[David Woolley]

On 24/08/2020 18:48, William Unruh wrote:
> You need it to be
> fixed, eg to the stars.

The stars move, and, in any case, most people want solar time, not
sidereal time. Even solar time varies throughout the year. I think the
"mean" in GMT refers to the fact that midnight is only true on average.

Sidereal time still needs a reference point on the earth that is in
earth surface coordinates, not galactic ones.

[Uwe Klein]

The traceroute tool should give you an incling about location.
( if route tracing is allowed and the routers names resolve.
often provider routers have geo identifiers:

Forex:
traceroute to time-a-g.nist.gov (129.6.15.28), 30 hops max, 40 byte
packets using UDP
1 zzz.box (182.168.179.1) 0.277 ms 0.345 ms 0.256 ms
2 p3e9bf135.dip0.t-ipconnect.de (62.155.241.53) 20.464 ms 20.144
ms 20.726 ms
3 f-eh1-i.F.DE.NET.DTAG.DE (62.154.18.70) 30.226 ms 29.796 ms
29.851 ms
4 * * *
5 * * *
6 CenturyLink-level3-NewYork6.Level3.net (4.68.70.50) 119.547 ms
118.809 ms 118.944 ms
7 dca-edge-22.inet.qwest.net (67.14.6.142) 119.632 ms 119.404 ms
119.341 ms
8 204.98.157.238 (204.98.157.238) 123.446 ms 122.953 ms 124.012 ms

doesn't work as well as it used to work.

Uwe

[Rob van der Putten]

Hi there


On 24/08/2020 16:07, William Unruh wrote:

<Cut>

> It was renamed because UTC has nothing to do with Greenwich. For
> historical reasons, the time at Greenwich is the same as UTC.

They are not perfectly identical. The difference is however less then
one second;
GMT is mean solar time.
UTC is TAI (atomic time) + leap seconds.

<Cut>


Regards,
Rob

[David Taylor]

Whilst this may be true, in practice people use GMT when they mean UTC.

BTW: GMT is mean solar time /at Greenwich/.

What annoys me is when Raspberry Shake and others refer to "UTC time"!

--
Cheers,
David
Web: http://www.satsignal.eu

[William Unruh]

Why? Repetition? Is PST time also annoying?
Universal Time Coordinate time is not really repetitious anyway, since
the noun is Coordinate. And UTC time means the type of time defined by
UTC-- since there are lots of other types of time one could use--
including decimal time ( 100 sec/min/ 100min/hr, 10hr/day)
>

[David Woolley]

On 15/09/2020 23:20, William Unruh wrote:
> the noun is Coordinate

The noun is Time. The C* is an adjective, coordinated or coordonné. It
appears the abbreviation is not in correct word order for either of
French or English:
<https://en.wikipedia.org/wiki/Coordinated_Universal_Time#Etymology>.