"Precision" time keep. Very interesting!

[VinNoDate401]

Hey guys,

So, just now (1:50 PM) I made a VERY interesting observation. President Obama is presenting a live speech right now on CNN. I have noticed that the White House time that is displayed in the top left corner differs than my iPhone time by 15 or so seconds.

The reason why I noticed this is because I have a sort of obsession of precise time keeping (I know, it's a mechanical watch, not a quartz! I know there will be variations) BUT I have been observing through my iPhone the seconds on my Rolex Sub Y serial 2002 no date. I synced the two about three weeks ago and since then the iPhone says it has gained 13 seconds but When synced with CNN it gained about 2 seconds!!

Very interesting. Please tell me which is more accurate to sync to. White House time or iPhone time? Is my Rolex gaining or losing? Losing if compared with iPhone but gaining 2 seconds if compared with CNN White House time.

Respectfully,



Vin

[beshannon]

I would use the iPhone.

You have no idea how/where a CNN feed is coming from and how many satellite trucks and networks that has to bounce through. You also have no idea what they calibrate against.

I sync my watches to two iPhone apps and it is funny, 1 week my local news radio station will be right on with my watch and the next week (after I have checked my watch and adjusted it again) they will be 30 seconds plus or minus with their stupid little tone.

I have begun to think they make up the time so they can believe they are deciding when to start and end segments.

[Micha]

Time displayed on TV may not be as accurate as you may think. There is actually a delay, depending on satellite feed and/or cable feed. Use this instead: http://www.time.gov/

[Nav01L]

According to uhrzeit.org, my iPhone really isn't accurate at all. It diverges by two min from the atomic clock. Unlike my GMT which is scarily accurate. It's been set over two weeks ago and diverges by about 1/4 of a second as of today.

[Bangel]

Originally Posted by Micha

Time displayed on TV may not be as accurate as you may think. There is actually a delay, depending on satellite feed and/or cable feed. Use this instead: http://www.time.gov/

x2

I've seen the variable delay first hand. At my gym there is a wall of televisions set to different channels. Sometimes when there is an important "live event" being broadcast on multiple stations, I can see they are out of sync with one another.

[joe100]

Yeah almost all major broadcasts like that are on a delay. Garment malfunctions etc etc

[VinNoDate401]

Great, so my sub is behind 11 seconds! Is that bad for 3 weeks? I'm being paranoid, aren't I? The COSC standards are in the context of ONE DAY, correct? So -4/+6 or something like that WITHIN A SINGLE DAY?

[beshannon]

Originally Posted by Nav01L

According to uhrzeit.org, my iPhone really isn't accurate at all. It diverges by two min from the atomic clock. Unlike my GMT which is scarily accurate. It's been set over two weeks ago and diverges by about 1/4 of a second as of today.

Interesting, I have no idea what the site is that you linked but I just checked my iPhone apps, Gorgy Timing and Emerald Time against Time.gov and all three agree to the second.

I'll stick with my iPhone apps, they seems spot on to me.

[77T]

Originally Posted by Nav01L

According to uhrzeit.org, my iPhone really isn't accurate at all. It diverges by two min from the atomic clock. Unlike my GMT which is scarily accurate. It's been set over two weeks ago and diverges by about 1/4 of a second as of today.

If you enabled "Set Automatically" in Settings>General>Date&Time on your iPhone, then you are on Network time which uses Stratum III/Ce133 clock sources. Latency is in milliseconds.

If not, then you could be off by some minutes over a year's time.

[77T]

Originally Posted by Micha

Time displayed on TV may not be as accurate as you may think. There is actually a delay, depending on satellite feed and/or cable feed. Use this instead: http://www.time.gov/

Originally Posted by Bangel

x2

I've seen the variable delay first hand. At my gym there is a wall of televisions set to different channels. Sometimes when there is an important "live event" being broadcast on multiple stations, I can see they are out of sync with one another.

Originally Posted by joe100

Yeah almost all major broadcasts like that are on a delay. Garment malfunctions etc etc

Inserted delay is the prime source - it varies by Network but usually about 6 seconds. Next replication delay from Network feed to distribution (Sat or Cable or both). Then signal regen along the path in cable. And lastly processing in your cable box.

Ergo, my sigline

[Watch Professor]

Originally Posted by VinNoDate401

Great, so my sub is behind 11 seconds! Is that bad for 3 weeks? I'm being paranoid, aren't I? The COSC standards are in the context of ONE DAY, correct? So -4/+6 or something like that WITHIN A SINGLE DAY?

11 seconds for three weeks is terrific. Yes, -4, +6 is for a 24 hour period.

[VinNoDate401]

Originally Posted by Watch Professor

11 seconds for three weeks is terrific. Yes, -4, +6 is for a 24 hour period.

That you Professor. I'm glad to hear it!

[George Ab]

http://www.time.gov/

[Nav01L]

Originally Posted by 77T

If you enabled "Set Automatically" in Settings>General>Date&Time on your iPhone, then you are on Network time which uses Stratum III/Ce133 clock sources. Latency is in milliseconds.

If not, then you could be off by some minutes over a year's time.

I would really like to do that, but when I do, it constantly sets me back an hour, it really doesn't like being in Switzerland... I've had this problem only with the 4s, not on any iPhone before that, tech support at the Genius Bar have no clue why my phone does that either.

[iain.cx]

Originally Posted by 77T

If you enabled "Set Automatically" in Settings>General>Date&Time on your iPhone, then you are on Network time which uses Stratum III/Ce133 clock sources. Latency is in milliseconds.

I found "Set Automatically" to be wildly wrong when using the UK Vodafone network, though I'm not sure whether that was because my phone was not running the latest software, it didn't have the latest carrier profile, Vodafone's network didn't have the right time or some other reason. Cursory Googling reveals all of the above are plausible.

My phone is jailbreaked so for The Best results I installed ntpd on it and it was quite happy thereafter. With neither ntpd nor "Set Automatically" the phone quickly drifts.

[SPACE-DWELLER]

I sync my watches to wwp.greenwichmeantime.com

Also, I have the App "Emerald Time" on my iPhone... it's an atomic clock pulling time from the nearest server.

[mrbill2mrbill2]

I use this for setting the time:

http://www.time.gov/widget.html

[submariner66]

Originally Posted by Micha

Time displayed on TV may not be as accurate as you may think. There is actually a delay, depending on satellite feed and/or cable feed. Use this instead: http://www.time.gov/

Oh my god this damn watch of mine is right on the money! Holy smokes.

Good link.

[Nav01L]

ImageUploadedByTapatalk1352936504.332746.jpg

Here you have it, my iPhones clock is way off doesn't mean any iPhone would be though, it must be an isolated issue.

[submariner66]

Try this phone number on this link...
http://tycho.usno.navy.mil/voice.html

[SPACE-DWELLER]

Originally Posted by Nav01L

Attachment 329408

Here you have it, my iPhones clock is way off doesn't mean any iPhone would be though, it must be an isolated issue.

The clock of my iPhone is off by - 19,212 seconds. Just checked.

[submariner66]

Originally Posted by SPACE-DWELLER

The clock of my iPhone is off by - 19,212 seconds. Just checked.

Thats funny you should make that your signature line!!

[Nav01L]

Originally Posted by SPACE-DWELLER

The clock of my iPhone is off by - 19,212 seconds. Just checked.

Thanks mate... I feel less lonely now ;)

Great solidarity in this Forum!

[Andad]

I sync my watches with my Seiko Astron.

[93 Turbo]

Aside from Eddie's Astron, buy a GPS in order to get spot on time or set your watch regularly to USN atomic clock.

[padi56]

Originally Posted by VinNoDate401

Hey guys,

So, just now (1:50 PM) I made a VERY interesting observation. President Obama is presenting a live speech right now on CNN. I have noticed that the White House time that is displayed in the top left corner differs than my iPhone time by 15 or so seconds.

The reason why I noticed this is because I have a sort of obsession of precise time keeping (I know, it's a mechanical watch, not a quartz! I know there will be variations) BUT I have been observing through my iPhone the seconds on my Rolex Sub Y serial 2002 no date. I synced the two about three weeks ago and since then the iPhone says it has gained 13 seconds but When synced with CNN it gained about 2 seconds!!

Very interesting. Please tell me which is more accurate to sync to. White House time or iPhone time? Is my Rolex gaining or losing? Losing if compared with iPhone but gaining 2 seconds if compared with CNN White House time.

Respectfully,



Vin

I lost all this constant time checking for the absolute second many many years ago.And doubt today if anyones life is run to the absolute second if it does then I feel truly sorry for anyone.And after wearing Rolex watches for well over 30 years cannot remember being late or ever missing a appointment.Or come to that missing a bus, train, or plane,and even at the bottom of the scale Rolex watches are 99.994% accurate.So even if you check once a month and reset you would be only say just a couple of minutes out.Myself now check once a week or so because whats in a few seconds either way out of 86400 in a day.

[SPACE-DWELLER]

Originally Posted by directioneng

I sync my watches with my Seiko Astron.

Beautiful watch, Eddie!