BT8500 phone set - time display

[Harry Bloomfield, Esq.]

Where do these phones get there time from?

I remember setting them once around three years ago, when I installed them, but not touched their time/date since.

Late yesterday evening, I spotted the time on the display was exactly 1 hour slow or behind, as if on BST. I made a mental note to check if there might be a DST setting in the phone, but later today I noticed the time was correct.

The only thing I can think of, is that that phone line has not been rung since the change to GMT on Sunday. except it rang at 09:30 this morning with a call. Maybe the incoming call corrected the clock?

[NY]

"Harry Bloomfield"; "Esq." [e-mail]> wrote in message news:qpchtg$j4t$ [e-mail]...

I've never found that the time has corrected itself automatically. Certainly when the hour changed recently the clock was still wrong even after I'd received a phone call, so it looks as if the ringing signal and the caller ID doesn't update the clock.

I've always had to correct the clock manually, both if it drifts slightly and whenever the hour changes. It never occurred to me that it *might* correct itself automatically: it's just one of the various clocks (eg microwave, both our cars, DECT phone, SLR and compact cameras) that needs to be corrected manually the morning after an hour change. The cameras have a GMT/BST switch which applies exactly one hour change, but most need setting from scratch; the cameras also really need setting from scratch because they gain/lose slightly wrt a time source such as GPS/mobile phone, or NTP-synced computer clock.

[The Other Mike]

The time is carried with the alleged incoming phone number on the caller id string sent before the first ring iirc

If on BT or an openreach provided line then

use the line test facility Dial 17070 then dial 1 for ringback clear down wait for the ringback clear down Phone reset to correct time

The likes of a Sky provided exchange line won't have a customer accessible line test number.

The caller ID spec is at

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[Harry Bloomfield, Esq.]

The Other Mike formulated the question :

That's it then, thanks..

I'm on Plusnet, which is BT under the hood...

[NY]

That assumes the phone is capable of re-synchronising its local clock with the reference time in the caller ID. Based on other people's comments in this thread, it sounds as if the phone *can* resync itself, so it's strange I've never noticed this when the hour changes. I'll have to test it: set the clock manually to a time that is wrong by a few minutes and then ring the phone from my mobile to see if the clock changes its time to the correct one. Is the clock-sync a feature that is always on, or does it have to be enabled in a menu?

[The Other Mike]

'Siemens' Gigasets ancient and modern don't seem to do at all, but in my experience everything 'BT' branded fixed or cordless regardless of price point has for many years done it by default and while you can manually set it there is no option to disable this functionality.

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[alan_m]

I have a caller display unit of 15+ years vintage and that's exactly how the time display works on this unit. Remove power and batteries and the time is incorrect until the first incoming phone call. The same with clock changes - the first incoming call will correct the time or else it will remain an hour out.

[Chris Green]

Our Gigaset phones certainly change their time with GMT/BST. There's a setting in the base station that tells it where to get its time from if I remember right, a web NTP server.

[Harry Bloomfield, Esq.]

NY laid this down on his screen :

In my phone's menu, all I could find was time/date manual settings and

24/12 hour display. No mention of auto update or a DST option.

[Harry Bloomfield, Esq.]

Chris Green pretended :

It would need internet access to do that.

[NY]

I've just tried it: I manually set the time to a few minutes in the past and then phoned my landline from my mobile. The time immediately changed to the correct time. I've only had the phones 4 years, and I've never noticed before that the time corrects when there's an incoming call. Next time the hour changes I'll have to see whether it can cope with a larger change of 60 mins rather than a couple of mins - I wonder if there's any coding that prevents very large corrections to the time.

It's a shame there was nothing in the instructions that I could see which mentioned that the clock was resynchronised by caller ID, and that phoning from a mobile might be an easier way of correcting the time.

[Harry Bloomfield, Esq.]

NY explained on 31/10/2019 :

I didn't spot anything in my instructions either.

[Chris Green]

Not necessarily. The Gigaset base station needs to be on a LAN to enable it to be configured using its web configuration screens. Assuming there is some system on the LAN that knows the time then it can run an NTP server to provide the 'right' time to other systems on the LAN.

[Robin]

"Dear BT

I set my phone to Berlin time as I promised to phone an important potential customer there at noon (his time). I failed to do so because of your phone's undocumented feature whereby the phone's clock is set by incoming calls with CLI. That meant I'd wasted my time. Can I disable the function? If not, I seek £100 in order to replace the phones with ones which don't insist they know best."

[Brian Gaff (Sofa)]

Well, It would surely be out the other way if it had not been set, sounds to me like somebody set it the wrong way. Spring forward, fall back.

The clocks that have auto summer winter have gone wrong this time. I have two, a clock for the blind but free running, and a talking pendent clock. Both have the auto switch on but did not change. On further investigation it seems it may in fact change this coming weekend, as this year the US and the UK change on different weekends for reasons best known to themselves, so if they assume the dates will always agree, come Sunday morning both will be an hour out the other way. Bah humbug. Brian

[Max Demian]

Do you try to make telephone calls from your alarm clock?

[Harry Bloomfield, Esq.]

Brian Gaff (Sofa) formulated on Thursday :

All clocks, my mobile phone, my watch, PC's plus obviously now my landline phones receives time syncs, that leaves just the microwave and oven which need to be sorted manually by SWMBO, which she did without comment. I was rather distracted at the weekend so to be honest, I wasn't even aware the clocks changed. I did half notice that it was lighter on a morning, but it still didn't sink in until I spotted my landline phones were an hour out.

[Robin]

No. But I do use the alarm on my phone.

[michael adams]

[The Other Mike]

Must admit my comment was based on a very small sample :) An ancient (2007 ish) C460IP with voip and a web browser configurable basestation, and a handful of much more recent (model unknown) basic gigasets that just have a combined charger / POTS line interface cradle, no voip nor IP interface.

I checked again and the C460IP does not have any NTP capability

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