How does the watch keep it's time?

Piggie

macrumors G3
Original poster
Feb 23, 2010
8,365
2,653
Just looked at Apple's site and saw the 50 millisecond comment again.

Just struck me, how does it do that?
Is it acting like normal radio controlled watches and clocks do and picking up the time signals given off from stations around the country?

http://en.wikipedia.org/wiki/Radio_clock

Using this method ?
 

Julien

macrumors G4
Jun 30, 2007
11,267
4,217
Atlanta
This is probably more marketing to the high end watch users/makers rhetoric that about time keeping. Your iPhone sets the time every time it connects to GPS. GPS requires an accuracy of under 100ns in order to work accurately. So just syncing the aWatch to your iPhone every day or so will keep it well within the gigantic 50ms error.

GPS is a much more accurate timing signal than radio based time transmissions. The GPS timing signal is typically accurate to 10 nanoseconds. However, most gps receivers lose timing accuracy in the interpretation of the signal. A typical GPS receiver with a pulse per second output can provide an accuracy of 100 nanoseconds to 1 microsecond.
https://forums.macrumors.com/threads/1777499/

("How much more accurate can the Apple watch be over the iphone time?")
Didn't remember that thread and I posted twice in it.:D I bet the aWatch is more accurate than my memory.:eek:
 

Piggie

macrumors G3
Original poster
Feb 23, 2010
8,365
2,653
Thanks for the link.

Looked thru that thread, people seem to be suggesting it's only accurate when paired to the iPhone, getting it's time signal from the link?

I don't know if there is an official logo for what we call Radio Control watches.

That's what I was wondering I guess, if the watch gets its own time signal independent from the iPhone like a normal radio controlled watch does, as that tech is years old and must be very very mature and solid now for Apple to use.

I suppose we need to wait for more info from Apple as to if it's the watch that keeps itself accurate or the phone keeps the watch accurate.

I hope the watch does it, itself personally. The more independent the watch is, the happier I am.

Again, many thanks to the link to the thread about this :)
 

Julien

macrumors G4
Jun 30, 2007
11,267
4,217
Atlanta
Thanks for the link.

Looked thru that thread, people seem to be suggesting it's only accurate when paired to the iPhone, getting it's time signal from the link?

I don't know if there is an official logo for what we call Radio Control watches....

I hope the watch does it, itself personally. The more independent the watch is, the happier I am.

Again, many thanks to the link to the thread about this :)
There is no official logo but they are often called Radio or Atomic clocks. While this is accurate it requires a long antenna and another radio receiver. Also it uses VLF (60kHz) and is less accurate (in absolute terms) than GPS.

The aWatch will need to piggy back on the iPhone for installing any Apps (the aWatch will only connect to the iPhone and not iTunes or the internet). It's been reported that you will have an App on your iPhone that controls /installs/configures Apps. The aWatch will probably gather data but offload it to the iPhone for processing (to save batt life). Also you will (probably) need to download all types of data like weather from the iPhone. You may need it to pair it to authorize your account for security every day or so. I bet you WILL need to pair your aWatch very often to your iPhone.
 

Piggie

macrumors G3
Original poster
Feb 23, 2010
8,365
2,653
There is no official logo but they are often called Radio or Atomic clocks. While this is accurate it requires a long antenna and another radio receiver. Also it uses VLF (60kHz) and is less accurate (in absolute terms) than GPS.

The aWatch will need to piggy back on the iPhone for installing any Apps (the aWatch will only connect to the iPhone and not iTunes or the internet). It's been reported that you will have an App on your iPhone that controls /installs/configures Apps. The aWatch will probably gather data but offload it to the iPhone for processing (to save batt life). Also you will (probably) need to download all types of data like weather from the iPhone. You may need it to pair it to authorize your account for security every day or so. I bet you WILL need to pair your aWatch very often to your iPhone.
Thanks.
It's almost sounding worse by the minute! :eek:
But I suppose it will work ok for people who are organised enough to keep both devices happy with each other daily. :)
 

fisha

macrumors regular
Mar 10, 2006
165
11
I don't see too much of an issue with the watch pairing (or more to the point, syncing) every day ... once it wakes up, it'll probably look for the phone nearby, and probably auto-sync with it for basic data. That pairing will probably be transparent and automatic based on the last sync. In the same way bluetooth car modules auto link and sync contacts to the phone when you jump in the car.

I do agree that for payments and the like of higher security data, then a security check will be required. I read the comment that for payments, with the watch being worn, you'd do a security check such as entering a pin, and that would be valid for the time that you kept the watch on your wrist. If you were to take the watch off and then put it back on, then the security pin would be required again for you to make a further payment transaction . . . which kind of makes sense . . . so that you couldn't have the watch taken from you to make stolen payments.
 

kdarling

macrumors P6
Every time a notification gets sent from the phone to the watch, it could (and probably will) include the current time down to the millisecond. Thus the watch's onboard time would be constantly updated.

Hmm. I've read that some $15 quartz watches are good to 1ms a day. So, 50ms could actually be pretty poor for a companion smartwatch :)

--

It feels like something that came from an engineer during a brainstorming session with the ad writers.

Publicist: "Okay, anything else besides the fact that 18kt gold is usually twice as strong as 24kt gold? We can spin that to sound amazing."

Engineer: "Oh, and it's never off by more than 50ms during the day."

Publicist: "Cool! Is that good? Never mind! If we just mention it, people will think it is!"

I think Apple has this down to a science. They can make anything sound magical.
 

APlotdevice

macrumors 68040
Sep 3, 2011
3,120
3,790
Every time a notification gets sent from the phone to the watch, it could (and probably will) include the current time down to the millisecond. Thus the watch's onboard time would be constantly updated.

Hmm. I've read that some $15 quartz watches are good to 1ms a day. So, 50ms could actually be pretty poor for a companion smartwatch :)

--

It feels like something that came from an engineer during a brainstorming session with the ad writers.

Publicist: "Okay, anything else besides the fact that 18kt gold is usually twice as strong as 24kt gold? We can spin that to sound amazing."

Engineer: "Oh, and it's never off by more than 50ms during the day."

Publicist: "Cool! Is that good? Never mind! If we just mention it, people will think it is!"

I think Apple has this down to a science. They can make anything sound magical.

My understanding is that the accuracy of a Quartz watch can vary considerably by its operating temperature.
 

HereBeMonsters

macrumors 6502
Jul 5, 2012
319
7
Fareham, UK
There is no official logo but they are often called Radio or Atomic clocks. While this is accurate it requires a long antenna and another radio receiver. Also it uses VLF (60kHz) and is less accurate (in absolute terms) than GPS.
I think you're getting a bit confused here.

Atomic clocks are ridiculously accurate clocks that typically use Caesium or Rubidium cooled to near absolute zero and calculate their time based on electron decay of the element.

Radio clocks are a consumer device that synchronise their time from radio signals - in Europe, at least, this is typically RDS radio - the same thing that tells you the name of the FM station you're listening to.

Neither of them require a massive aerial - I have 4 of the latter at home!
 

HereBeMonsters

macrumors 6502
Jul 5, 2012
319
7
Fareham, UK
No I am not.
Yeah, those are not by any stretch of the imagination actual atomic clocks.

Wikipedia said:
Atomic clock
From Wikipedia, the free encyclopedia
For a clock updated by radio signals which is sometimes called an "atomic clock", see Radio clock.
Sorry, I'm not trying to argue with you here, just clarify the information. You will not get an atomic clock in your house. Not unless you live in a science lab.

They sometimes call radio controlled clocks atomic clocks, as that is where they get their time signals from.

For a watch, this is indeed possible - I have about five or so that connect to the signal from Anthorn, as well as my bedside alarm clock that does so. The Apple Watch will not do this, however - it will merely have a computer and sync itself to the phone every now and then.
 

rotation

macrumors member
Oct 16, 2014
80
0
Los Angeles
From what I understand it has an internal chronometer and then receives updates from the cell network giving it extremely accurate timekeeping.


I am not totally sure if it's really possible for it to keep much better time than an analog watch but who knows.
 

Julien

macrumors G4
Jun 30, 2007
11,267
4,217
Atlanta
Yeah, those are not by any stretch of the imagination actual atomic clocks....
Yeah, and if you would have read my post you would know that was not what I was talking about. I was responding to a question in the previous post.

piggie said:
...I don't know if there is an official logo for what we call Radio Control watches....
And my response.

Julien said:
There is no official logo [for radio clocks] but they are often called Radio or Atomic clocks.
My response IS correct and my pics prove it. Is this still not clear what I was talking about?
 
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