Daylight time change. How does this happen?

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raytaylor

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#603310 1-Apr-2012 15:09

radio clocks

The US military transmits time beacons at very high power from sites across the world in the AM and lower FM frequency ranges which are picked up by all sorts of devices.
As part of the beacon that is transmitted, there is a flag that allows them to switch DST on and off.

Ray Taylor

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Dingbatt

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#603342 1-Apr-2012 16:19

Hobchild:
sbiddle:
Hobchild: It can be frustrating at times for people like me who use our phones as alarms and sometimes work on Sundays. It all depends on how much trust we put in our phones. I personally always force the change before I go to bed if I'm working the next day now (was late once).

But if you force the change your phone will?still automatically change itself.?

You can turn off auto update, well at least you can with every phone I've owned. Although more modern ones have just had the option to turn DLS on/off when you choose the time zone.?

That's why I find it reassuring on my HTC phones (Android) that when I set an alarm it tells me how many hours until it is going to sound. I have needed it several times for daylight saving change-overs and it hasn't failed me yet.

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Technofreak

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#603383 1-Apr-2012 17:32

Dingbatt: That's why I find it reassuring on my HTC phones (Android) that when I set an alarm it tells me how many hours until it is going to sound. I have needed it several times for daylight saving change-overs and it hasn't failed me yet.

Symbian does exactly the same. A very handy feature.

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oxnsox

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#603459 1-Apr-2012 20:07

raytaylor: radio clocks

The US military transmits time beacons at very high power from sites across the world in the AM and lower FM frequency ranges which are picked up by all sorts of devices.
As part of the beacon that is transmitted, there is a flag that allows them to switch DST on and off.

And here was I thinking it had something to do with Huawei....

KevinL

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#603468 1-Apr-2012 20:22

oxnsox:
raytaylor: radio clocks

The US military transmits time beacons at very high power from sites across the world in the AM and lower FM frequency ranges which are picked up by all sorts of devices.
As part of the beacon that is transmitted, there is a flag that allows them to switch DST on and off.

And here was I thinking it had something to do with Huawei....

Not particularly relevant to consumer cellphones though - occasionally they may source a time signal from the cell network, or occasionally by polling an internet time server (e.g. time.nist.gov) but I've never heard of a phone that synchronises to terrestrial phone signals.

Curiously, while the nearest radio time signal station in Kyushu, Japan only has a range of 1000km, under the right atmospheric conditions my Citizen watch (a JDM PMV65-2271) will synchronise to the radio time signal. My vague understanding is the long-wave radio signal can bounce of the ionosphere - very hit and miss, but pretty amazing given how far away we are.

raytaylor

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#603531 2-Apr-2012 00:51

KevinL:
oxnsox:
raytaylor: radio clocks

The US military transmits time beacons at very high power from sites across the world in the AM and lower FM frequency ranges which are picked up by all sorts of devices.
As part of the beacon that is transmitted, there is a flag that allows them to switch DST on and off.

And here was I thinking it had something to do with Huawei....

Not particularly relevant to consumer cellphones though - occasionally they may source a time signal from the cell network, or occasionally by polling an internet time server (e.g. time.nist.gov) but I've never heard of a phone that synchronises to terrestrial phone signals.

Curiously, while the nearest radio time signal station in Kyushu, Japan only has a range of 1000km, under the right atmospheric conditions my Citizen watch (a JDM PMV65-2271) will synchronise to the radio time signal. My vague understanding is the long-wave radio signal can bounce of the ionosphere - very hit and miss, but pretty amazing given how far away we are.

A quick wikipedia search will tell you that today is april fools day, and that we dont have radio clock service covering consumer devices in New Zealand.

Ray Taylor

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KevinL

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#603533 2-Apr-2012 01:40

raytaylor:
KevinL:
oxnsox:
raytaylor: radio clocks

The US military transmits time beacons at very high power from sites across the world in the AM and lower FM frequency ranges which are picked up by all sorts of devices.
As part of the beacon that is transmitted, there is a flag that allows them to switch DST on and off.

And here was I thinking it had something to do with Huawei....

Not particularly relevant to consumer cellphones though - occasionally they may source a time signal from the cell network, or occasionally by polling an internet time server (e.g. time.nist.gov) but I've never heard of a phone that synchronises to terrestrial phone signals.

Curiously, while the nearest radio time signal station in Kyushu, Japan only has a range of 1000km, under the right atmospheric conditions my Citizen watch (a JDM PMV65-2271) will synchronise to the radio time signal. My vague understanding is the long-wave radio signal can bounce of the ionosphere - very hit and miss, but pretty amazing given how far away we are.

A quick wikipedia search will tell you that today is april fools day, and that we dont have radio clock service covering consumer devices in New Zealand.

A quick Wikipedia search will also tell you that traditionally April Fool's Day is only observed until midday.

We don't officially have radio time signal coverage in New Zealand, but watches and clocks capable of receiving the signal are certainly available for purchase - and as mentioned, occasionally manage to sync to the JJY signal as mine has just done this evening.