Alan Browne

On 2012-01-11 16:46 , Chris Blunt wrote:

> I was wondering if perhaps the iPhone uses a NTP time reference source
> when it has an active internet connection available.

It's not clear to me.

I have an App called Time which allows me to enter an ntp address (so I
use one nearby). It's not clear if this changes the system ntp or is a
separate process using a separate ntp server while the iPhone uses its own.

Generally Mac's come set to the super regional Apple ntp server.
(time.apple.com, time.asia.apple.com, time.euro.apple.com). I assume
the iPhone uses those same defaults. (I set my Mac to a local one).

--
"We demand rigidly defined areas of doubt and uncertainty."
Douglas Adams - (Could have been a GPS engineer).

JF Mezei

Alan Browne wrote:

> I have an App called Time which allows me to enter an ntp address (so I
> use one nearby). It's not clear if this changes the system ntp or is a
> separate process using a separate ntp server while the iPhone uses its own.


If you read the docunention, it is clearly wirtten that because IOS does
not allow an application to change the time, the "Time" application does
not change the iphone's time. It mereley reports the offet to the reat
(ntp obtained) time.

Fergus McMenemie

Wes Groleau <Groleau+news@FreeShell.org> wrote:

> > I get similar results to you. I often check my iPhone time against the
> > Greenwich Time Signal broadcast on the radio station I listen to in
>
> P.S. There's a free app called Emerald Time (I think that's the name)
> that will use NTP to show how far off your phone is.

Emerald time is good. But it ony reports using NTP how out the Iphone
is. Travelling to/from different time zones via the channel tunnel, I
was badly caught out several times by the Iphone not changing time zone
properly. THERE IS A BUG SOMEWHERE. But I was not able to pin down what
was going on. In some cases as I roamed about within Europe I could see
the clock jump as I roamed to different networks. I suspect there is a
glitch within IOS which stops the Iphone from properly interpreting what
is being sent out by the local tower.

nospam

In article <1kdzfoo.1oqq4pq14ggjg8N%fergus@twig-me-uk.not.here>, Fergus
McMenemie <fergus@twig-me-uk.not.here> wrote:

> Emerald time is good. But it ony reports using NTP how out the Iphone
> is. Travelling to/from different time zones via the channel tunnel, I
> was badly caught out several times by the Iphone not changing time zone
> properly. THERE IS A BUG SOMEWHERE. But I was not able to pin down what
> was going on. In some cases as I roamed about within Europe I could see
> the clock jump as I roamed to different networks. I suspect there is a
> glitch within IOS which stops the Iphone from properly interpreting what
> is being sent out by the local tower.

the only glitch is that apple does not understand time zones. macs have
time zone issues too.

Wes Groleau

On 01-16-2012 16:48, Fergus McMenemie wrote:
>> > P.S. There's a free app called Emerald Time (I think that's the name)
>> > that will use NTP to show how far off your phone is.
> Emerald time is good. But it ony reports using NTP how out the Iphone

That's what I said.

--
Wes Groleau

People would have more leisure time if it weren't
for all the leisure-time activities that use it up.
— Peg Bracken

Dillon Pyron

Thus spake nospam <nospam@nospam.invalid> :

>In article <jeg3jj$deo$2@dont-email.me>, Wes Groleau
><Groleau+news@FreeShell.org> wrote:
>
>> > it could be at&t. the time they send is usually off by up to a minute,
>> > sometimes more, so it wouldn't surprise me if the time zone was wrong.
>>
>> Every time I've checked (not very often), my AT&T iPhone is about three
>> seconds off.
>
>my at&t phone is usually about 20-30 seconds off. not a huge deal, but
>it's still wrong. sprint & verizon, on the other hand, are exact (they
>have to be).

My AT&T iPhone, AT&T home phone (not Uverse), my TW cable box and my
Vista laptop all disagree by about 45 seconds. Never consistently!

I "trust" my laptop the most. It is consistenly late from my GPS,
which I credit as the most "accurate" and "precise". When I have 6 or
more sattelites in view.

It depends on the delays from the source to the transmitter to you.

Any Unix sysdamins out there? My answer to most questions of "can
you?" or "why does it?" is almost always "it depends". I was told
long ago in SunOS school that that is the correct answer. Unless it's
a multiple choice question. The it's "yes".
--

- dillon I am not invalid

So Kim Jung Ill shows up at the barbecue. "Wait,"
says Qadaffi, "you don't have any peircings." "If you
starve your people enough they'll be too weak to rebbel."
"You have the same number of holes in your head as when
you were born," says bin Laden. "My compound had radar
and antiacraft misslles." "Your neck," shouted Hussein,
"it's the same length." "I didn't piss on W's father."
"Then what happened?" the three asked. "Damned counterfiet
Lipitor and insulin!"

Matt Simpson

Back to my original question, which involved the timezone and not the
precise time, it gets curiouser and curiouser.

I'm not completely convinced that the cell tower is telling the iPhone
what timezone it's in. Or to be more correct, maybe the cell tower is
telling it, but the iPhone is ignoring that in favor of some other
source.

For one thing, I've noticed that the timezone doesn't change immediately
when I get home. It stays correct for a while. It seems to change
overnight.

Also, the displayed time doesn't seem to change zones while the screen
is locked. When I picked up my phone this morning, it had the correct
time. As soon as I unlocked the screen, the time dropped back an hour.

After being at work about an hour, I noticed the time displayed on the
locked screen was still an hour behind. I unlocked the screen and it
immediately jumped ahead.

There's something very mysterious happening overnight that's causing my
phone to think it's in a different timezone. At this point, I'm not
even sure it's related to location. I haven't spent a night with the
phone somewhere else to see if it changes timezones elsewhere.