Time Zones When Traveling.

[Ken Blake]

I have a Pixel 4a. What happens to its display of the time when
traveling on an airplane? Does the time zone change automatically as
needed, or do I have to do it manually?

I also have a Garmin Venu SQ watch. Does the time on it synch to the
phone, or do I also have to do that manually?

[Carlos E.R.]

It takes the local time of the network provider when you arrive at
destination. Not specific about the Pixel.


--
Cheers, Carlos.

[Frank Slootweg]

Ken Blake <K...@invalid.news.com> wrote:
> I have a Pixel 4a. What happens to its display of the time when
> traveling on an airplane? Does the time zone change automatically as
> needed, or do I have to do it manually?

Normally it stays at the time zone of the origin and switches to the
time zone of the destination as soon as your phone picks up the mobile
('cell') network there.

If you switch off flight-mode during the flight - which you shouldn't -
it might pick up a cell tower en-route (and set the timezone
accordinly), but with a normal commercial flight that's highly unlikely.

> I also have a Garmin Venu SQ watch. Does the time on it synch to the
> phone, or do I also have to do that manually?

Depends on the watch. My Fitbit Charge 4 syncs with the phone (but
sometimes needs an Internet connection as well).

[Chris]

Ken Blake <K...@invalid.news.com> wrote:
> I have a Pixel 4a. What happens to its display of the time when
> traveling on an airplane? Does the time zone change automatically as
> needed, or do I have to do it manually?

It'll pick up the correct timezone whenever you connect to a local network.

[Carlos E.R.]

Define correct :-)

Things get interesting when you are near a frontier (or time zone
frontier), and each side keeps different time zones or different summer
time switch. Or the mobile network provider keeps a different time zone,
that is :-)

--
Cheers, Carlos.

[Ken Blake]

On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
wrote:

>Ken Blake <K...@invalid.news.com> wrote:
>> I have a Pixel 4a. What happens to its display of the time when
>> traveling on an airplane? Does the time zone change automatically as
>> needed, or do I have to do it manually?
>
> Normally it stays at the time zone of the origin and switches to the
>time zone of the destination as soon as your phone picks up the mobile
>('cell') network there.

Thanks. Carlos said the same thing, so I guess you're both right. <G>

>
> If you switch off flight-mode during the flight - which you shouldn't -
>it might pick up a cell tower en-route (and set the timezone
>accordinly), but with a normal commercial flight that's highly unlikely.
>
>> I also have a Garmin Venu SQ watch. Does the time on it synch to the
>> phone, or do I also have to do that manually?
>
> Depends on the watch. My Fitbit Charge 4 syncs with the phone (but
>sometimes needs an Internet connection as well).

I think mine also does, but I'm not sure, and that's why I asked.

[Chris in Makati]

On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
wrote:

> If you switch off flight-mode during the flight - which you shouldn't -
>it might pick up a cell tower en-route (and set the timezone
>accordinly), but with a normal commercial flight that's highly unlikely.

Also if you use in-flight wi-fi it can change the time zone to
something completely different. Presumably it's the time zone of
wherever the internet gateway is on the ground is located.

Chris

[Chris in Makati]

When I was in the Canary Isles my phone adjusted to Spanish time,
which was incorrect by 1 hour because there's a time difference to
mainland Spain. I had to set the time manually to get it correct.

Chris

[Carlos E.R.]

That's strange, unless you are talking of Windows.

--
Cheers, Carlos.

[Carlos E.R.]

On 2023-07-02 05:22, Chris in Makati wrote:

Were you using a Spanish provider? That's strange, I have not heard of
this problem.

I'm almost sure that the GSM provided time is correct for the islands,
and the distance to the mainland makes it impossible to connect to a
tower on the mainland. However, time via internet works differently,
there could be an issue there.

Hum. It seems that there are indeed problems with Movistar.

<https://comunidad.movistar.es/t5/Soporte-M%C3%B3vil/Hora-autom%C3%A1tica-en-Canarias/td-p/1246476>

<https://comunidad.movistar.es/t5/Soporte-M%C3%B3vil/Hora-automatica-en-Canarias/td-p/3138439>


--
Cheers, Carlos.

[Chris]

True I guess. Although, I've never been in that situation. I suppose the
Spain/Portugal border is one such place.

I know at Freiburg-Mulhouse-Basel Airport can be a problem as you can end
up on a non-EU network which can be expensive for some.

[Ken Blake]

On Sun, 02 Jul 2023 11:22:33 +0800, Chris in Makati <ma...@nospam.com>
wrote:

>On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
>wrote:
>
>> If you switch off flight-mode during the flight - which you shouldn't -
>>it might pick up a cell tower en-route (and set the timezone
>>accordinly), but with a normal commercial flight that's highly unlikely.
>
>Also if you use in-flight wi-fi

I won't. Too expensive and not needed.

[Frank Slootweg]

Chris in Makati <ma...@nospam.com> wrote:

As Carlos also mentioned. this shouldn't happen, because the phone
should get the time from the *mobile* ('cell') network, not from a Wi-Fi
network. OTOH, a smartphone is a bit of a computer, so some smartphone
could get the time from 'the Internet' via NTP (Network Time Protocol).

[Frank Slootweg]

Ken Blake <K...@invalid.news.com> wrote:
> On Sun, 02 Jul 2023 11:22:33 +0800, Chris in Makati <ma...@nospam.com>
> wrote:
>
> >On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
> >wrote:
> >
> >> If you switch off flight-mode during the flight - which you shouldn't -
> >>it might pick up a cell tower en-route (and set the timezone
> >>accordinly), but with a normal commercial flight that's highly unlikely.
> >
> >Also if you use in-flight wi-fi
>
> I won't. Too expensive and not needed.

Many airlines, especially on international flights (you're flying to
Italy, aren't you?) offer free Wi-Fi for *messaging*, i.e. things like
WhatsApp, iMessages, etc., 'even' in economy class. We/I used it to
keep in touch with the homefront during our flights to/from Australia
(via the US! :-)) and my flights to/from the US.

[...]

[Carlos E.R.]

Indeed.

I seem to recall that Niagara Falls (I was on the Canada side) was
another area.

And from what Chris in Makati says, the Canary Islands is another (at
least with one provider). I was there long ago, before smartphones, so I
have forgotten.

--
Cheers, Carlos.

[Carlos E.R.]

Yes. But NTP uses UTC, not local time. There is no zone information in
NTP protocol.

But computers using the Windows method to setup time, those can be
affected, they use "local" time.

--
Cheers, Carlos.

[Carlos E.R.]

That's nice :-)

>
> [...]

--
Cheers, Carlos.

[Frank Slootweg]

Carlos E.R. <robin_...@es.invalid> wrote:
> On 2023-07-02 19:55, Frank Slootweg wrote:
> > Chris in Makati <ma...@nospam.com> wrote:
> >> On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
> >> wrote:
> >>
> >>> If you switch off flight-mode during the flight - which you shouldn't -
> >>> it might pick up a cell tower en-route (and set the timezone
> >>> accordinly), but with a normal commercial flight that's highly unlikely.
> >>
> >> Also if you use in-flight wi-fi it can change the time zone to
> >> something completely different. Presumably it's the time zone of
> >> wherever the internet gateway is on the ground is located.
> >
> > As Carlos also mentioned. this shouldn't happen, because the phone
> > should get the time from the *mobile* ('cell') network, not from a Wi-Fi
> > network. OTOH, a smartphone is a bit of a computer, so some smartphone
> > could get the time from 'the Internet' via NTP (Network Time Protocol).
>
> Yes. But NTP uses UTC, not local time. There is no zone information in
> NTP protocol.

Oops! Brain fog! :-) Of course you're right.

Theoretically, the phone could get the UTC time by NTP and the
location - and hence the timezone - from GPS (or another location
source?), but that actually happening in a plane in full flight is highly
unlikely.

OTOH, if the phone used Wi-Fi location services and Google somehow
tracks the location of the Wi-Fi AP in the plane, it *could* work,
theoretically.

> But computers using the Windows method to setup time, those can be
> affected, they use "local" time.

But only if they know what location is "local", which won't happen in
a plane.

[Ken Blake]

On 2 Jul 2023 18:01:04 GMT, Frank Slootweg <th...@ddress.is.invalid>

wrote:

>Ken Blake <K...@invalid.news.com> wrote:
>> On Sun, 02 Jul 2023 11:22:33 +0800, Chris in Makati <ma...@nospam.com>
>> wrote:
>>
>> >On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
>> >wrote:
>> >
>> >> If you switch off flight-mode during the flight - which you shouldn't -
>> >>it might pick up a cell tower en-route (and set the timezone
>> >>accordinly), but with a normal commercial flight that's highly unlikely.
>> >
>> >Also if you use in-flight wi-fi
>>
>> I won't. Too expensive and not needed.
>
> Many airlines, especially on international flights (you're flying to
>Italy, aren't you?)

Yes. Rome.

>offer free Wi-Fi for *messaging*, i.e. things like
>WhatsApp, iMessages, etc., 'even' in economy class. We/I used it to
>keep in touch with the homefront during our flights to/from Australia
>(via the US! :-)) and my flights to/from the US.

I can wait until arrival and use the free WI-fin in the hotel. I hate
messaging, because it's very hard for me to type on the tiny keyboard.

>[...]

[Ken Blake]

On Sun, 2 Jul 2023 20:04:29 +0200, "Carlos E.R."

<robin_...@es.invalid> wrote:

>On 2023-07-02 12:51, Chris wrote:
>> Carlos E.R. <robin_...@es.invalid> wrote:
>>> On 2023-07-01 18:26, Chris wrote:
>>>> Ken Blake <K...@invalid.news.com> wrote:
>>>>> I have a Pixel 4a. What happens to its display of the time when
>>>>> traveling on an airplane? Does the time zone change automatically as
>>>>> needed, or do I have to do it manually?
>>>>
>>>> It'll pick up the correct timezone whenever you connect to a local network.
>>>
>>> Define correct :-)
>>>
>>> Things get interesting when you are near a frontier (or time zone
>>> frontier), and each side keeps different time zones or different summer
>>> time switch. Or the mobile network provider keeps a different time zone,
>>> that is :-)
>>
>> True I guess. Although, I've never been in that situation. I suppose the
>> Spain/Portugal border is one such place.
>>
>> I know at Freiburg-Mulhouse-Basel Airport can be a problem as you can end
>> up on a non-EU network which can be expensive for some.
>
>Indeed.

I know that airport, which I thought was just called Basel, from
having flown home from there after cruising down the Rhine several
years ago. I was very surprised to find that, despite its name, it
wasn't even in Switzerland.

[Chris in Makati]

On 2 Jul 2023 17:55:05 GMT, Frank Slootweg <th...@ddress.is.invalid>

I was using an iPhone, and the time definitely changed at some point
during the flight. I assumed it used Apple's Location Services to
determine that I was in a different time zone, but it definitely
didn't connect to a mobile network. My only connection with the
outside world was via a wi-fi connection I had used, or possibly a GPS
signal.

Chris

[Chris in Makati]

On Sun, 2 Jul 2023 12:33:09 +0200, "Carlos E.R."
<robin_...@es.invalid> wrote:

>> When I was in the Canary Isles my phone adjusted to Spanish time,
>> which was incorrect by 1 hour because there's a time difference to
>> mainland Spain. I had to set the time manually to get it correct.
>
>Were you using a Spanish provider? That's strange, I have not heard of
>this problem.

I was roaming during my visit there, but don't remember which Spanish
network I was connected to.

Chris

[Chris]

Me too when I flew to Basel a few years ago. You have to be very careful
when through border control as you'll end up in the wrong COUNTRY! :D

[Joerg Lorenz]

On 03.07.23 11:47, Chris wrote:
> Ken Blake <K...@invalid.news.com> wrote:
>> I know that airport, which I thought was just called Basel, from
>> having flown home from there after cruising down the Rhine several
>> years ago. I was very surprised to find that, despite its name, it
>> wasn't even in Switzerland.
>
> Me too when I flew to Basel a few years ago. You have to be very careful
> when through border control as you'll end up in the wrong COUNTRY! :D

Bullshit. All three countries on the Basel-Mulhouse Airport which is the
correct name are members of the Schengen Area.

--
Sent with Betterbird from a Silicon-Mac. Simply better.
www.betterbird.eu

[Carlos E.R.]

On 2023-07-02 22:19, Frank Slootweg wrote:
> Carlos E.R. <robin_...@es.invalid> wrote:
>> On 2023-07-02 19:55, Frank Slootweg wrote:
>>> Chris in Makati <ma...@nospam.com> wrote:
>>>> On 1 Jul 2023 13:34:06 GMT, Frank Slootweg <th...@ddress.is.invalid>
>>>> wrote:
>>>>
>>>>> If you switch off flight-mode during the flight - which you shouldn't -
>>>>> it might pick up a cell tower en-route (and set the timezone
>>>>> accordinly), but with a normal commercial flight that's highly unlikely.
>>>>
>>>> Also if you use in-flight wi-fi it can change the time zone to
>>>> something completely different. Presumably it's the time zone of
>>>> wherever the internet gateway is on the ground is located.
>>>
>>> As Carlos also mentioned. this shouldn't happen, because the phone
>>> should get the time from the *mobile* ('cell') network, not from a Wi-Fi
>>> network. OTOH, a smartphone is a bit of a computer, so some smartphone
>>> could get the time from 'the Internet' via NTP (Network Time Protocol).
>>
>> Yes. But NTP uses UTC, not local time. There is no zone information in
>> NTP protocol.
>
> Oops! Brain fog! :-) Of course you're right.
>
> Theoretically, the phone could get the UTC time by NTP and the
> location - and hence the timezone - from GPS (or another location
> source?), but that actually happening in a plane in full flight is highly
> unlikely.

On some plains GPS works. On the last one I tried, I could not get a
fix, the metal cabin impeded it, I guess. Just a month before, I could
track the approach path. I think it did not work at altitude.

>
> OTOH, if the phone used Wi-Fi location services and Google somehow
> tracks the location of the Wi-Fi AP in the plane, it *could* work,
> theoretically.
>
>> But computers using the Windows method to setup time, those can be
>> affected, they use "local" time.
>
> But only if they know what location is "local", which won't happen in
> a plane.

No, the people doing the initial configuration would setup the "locale"
for that Windows setup, and would probably never change. So, assume
headquarters.

Unless they have designed and run some application to track the flight
location and apply it (if it doesn't involve a reboot, I suspect).


--
Cheers, Carlos.

[Chris]

Joerg Lorenz <hugy...@gmx.ch> wrote:
> On 03.07.23 11:47, Chris wrote:
>> Ken Blake <K...@invalid.news.com> wrote:
>>> I know that airport, which I thought was just called Basel, from
>>> having flown home from there after cruising down the Rhine several
>>> years ago. I was very surprised to find that, despite its name, it
>>> wasn't even in Switzerland.
>>
>> Me too when I flew to Basel a few years ago. You have to be very careful
>> when through border control as you'll end up in the wrong COUNTRY! :D
>
> Bullshit. All three countries on the Basel-Mulhouse Airport which is the
> correct name are members of the Schengen Area.

All I can say is that when I went there were many, many signs making sure
you ended up in the correct country. Not sure what schengen has to do with
it...

[Frank Slootweg]

Sigh! More brain fog! :-(

I actually used the GPS in my Android tablet on a flight from
Darwin (Australia) to Singapore. That plane didn't have any personal
screen, so also no flight-path info. I wanted to know how we were
progressing, so I used the world map of the OsmAnd+ app with the
tablet's GPS, while holding the tablet near the window. Worked perfectly
fine.

So my described scenario is not "highly unlikely", it 'just' depends
on the right software (SMOP, Small Matter Of Programming) to use the
location from GPS and NTP via the plane's Wi-Fi network, to set the time
of the phone. (Don't know if the plane's Wi-Fi would allow a connection
to the NTP port.)

[...]

[Frank Slootweg]

Ah! An *iPhone*! That explains everything! (Just kidding.)

[Joerg Lorenz]

Am 03.07.23 um 17:05 schrieb Chris:

> Joerg Lorenz <hugy...@gmx.ch> wrote:
>> Bullshit. All three countries on the Basel-Mulhouse Airport which is the
>> correct name are members of the Schengen Area.
>
> All I can say is that when I went there were many, many signs making sure
> you ended up in the correct country. Not sure what schengen has to do with
> it...

That is an organisational issue. The Airport is located on French territory.

--
Gutta cavat lapidem (Ovid)

[Dave Royal]

Happened to my wife earlier this year, roaming on Movistar. She was using
the titsa app to find the next bus, so had to fix the time.

I vaguely recall I was roaming on Voda ES. I didn't notice if the time was
wrong.


--
(Remove numerics from email address)

[Chris]

Joerg Lorenz <hugy...@gmx.ch> wrote:
> Am 03.07.23 um 17:05 schrieb Chris:
>> Joerg Lorenz <hugy...@gmx.ch> wrote:
>>> Bullshit. All three countries on the Basel-Mulhouse Airport which is the
>>> correct name are members of the Schengen Area.
>>
>> All I can say is that when I went there were many, many signs making sure
>> you ended up in the correct country. Not sure what schengen has to do with
>> it...
>
> That is an organisational issue.

Exactly my point. You're adding what, exactly?

> The Airport is located on French territory.

No shit...

[Carlos E.R.]

Goof.plane or airplane

>> fix, the metal cabin impeded it, I guess. Just a month before, I could
>> track the approach path. I think it did not work at altitude.
>
> Sigh! More brain fog! :-(
>
> I actually used the GPS in my Android tablet on a flight from
> Darwin (Australia) to Singapore. That plane didn't have any personal
> screen, so also no flight-path info. I wanted to know how we were
> progressing, so I used the world map of the OsmAnd+ app with the
> tablet's GPS, while holding the tablet near the window. Worked perfectly
> fine.

I don't remember if I tried placing the phone at the window, maybe I did
not have a window seat.

> So my described scenario is not "highly unlikely", it 'just' depends
> on the right software (SMOP, Small Matter Of Programming) to use the
> location from GPS and NTP via the plane's Wi-Fi network, to set the time
> of the phone. (Don't know if the plane's Wi-Fi would allow a connection
> to the NTP port.)

I think it is a service provided by the "router", if it is a good one.
It will have a DHCP server, and I think time is one of the services it
can assign and say "ask the router". Some protocols need time in sync.

<https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol#Options>

See the table there, "time offset" is one posibility. "Time server" is
another.


It makes sense for the flight "router" to provide several services
locally instead of the expensive internet.


--
Cheers, Carlos.

[Carlos E.R.]

That there are no frontiers. Once outside, if you end on the "wrong
country" you can go around the airport to the intended one, without a
passport control (normally). Of course, not knowing the area this can be
quite inconvenient.

I did not know this peculiarity of that airport, so thanks for telling
us :-)

--
Cheers, Carlos.

[Chris]

I agree, not the end of the world but would waste quite a fair bit of time.

[Frank Slootweg]

I remember similar problems at Geneva airport, a long, long time ago,
pre-Schengen. You had to take the right route to and with your rental
car, so that the car from country X, didn't - even temporarily - end up
in country Y. For example my French rental car destined for (use in)
France, shouldn't touch Swiss territory, or hell would break loose! :-)

[Frank Slootweg]

Interesting! Thanks for the pointer. I didn't know DHCP had so many
other functions ('options').

Later on the Wikipedia page, it also specifically mentions 'Timezone',
so perhaps it's not even needed to use NTP nor GPS.

<https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol#Other_extensions>

Perhaps a network specialist can shed a light on whether or not it's
likely that a 'router' on board an airplane, would/could provide
timezone/NTP functionality to a Wi-Fi connected device of a passenger.
(AFAIK, CJ doesn't subscribe to this group.)

[Andy Burns]

Frank Slootweg wrote:

> On some plains GPS works. On the last one I tried, I could not get a
> fix, the metal cabin impeded it, I guess. Just a month before, I could
> track the approach path. I think it did not work at altitude.

You might exceed the CoCom limits if you use your GPS on a Virgin
Galactic flight, but not onboard any commercial flight since Concorde
retired :-P

[Frank Slootweg]

Actually Carlos wrote that. Credit/blame where it's due!

Luckily Carlos could *not* "get a fix"! :-)