Reply With QuoteHow did you check atomic time?
Hoping someone can explain this - when I did a GPS receive on my Citizen satellite wave watch and
checked it against atomic time there was a difference of approx 23 secs.
Why is this ?
maseman
How did you check atomic time?
Deleted as I was totally wrong.
Last edited by Dave+63; 11th March 2018 at 13:06.
I have the Citizen GPS satellite wave and a GW5000 atomic and just checked and they are they are correct to the same second.
Last edited by mjc1216; 11th March 2018 at 12:08.
Odd, n'est-ce pas? Actually, GPS time is NOT perturbed by leap seconds - and, as a result is now ahead by about 18 seconds! Possibly some watches correct for that, given some of the other posts here?!
[See e.g. http://leapsecond.com/java/gpsclock.htm ]
Not a lot of people know that!
I didn't...but should have. Thanks...Originally Posted by WatchIng
PS Does the GPS transmission include the current correction? Just off to look that up, but you may already know the answer.
Update: Yes, it does (link):
The GPS navigation message includes the difference between GPS time and UTC. As of January 2017, GPS time is 18 seconds ahead of UTC because of the leap second added to UTC on December 31, 2016. Receivers subtract this offset from GPS time to calculate UTC and specific timezone values. New GPS units may not show the correct UTC time until after receiving the UTC offset message. The GPS-UTC offset field can accommodate 255 leap seconds (eight bits).
Last edited by PickleB; 11th March 2018 at 12:30.
In the Citizen manual it tells you how to adjust for this but i suppose most people don't bother reading it and makes very little difference to the correct time.
Last edited by mjc1216; 11th March 2018 at 12:27.
So it does! In the version I downloaded:
When the time or calendar is incorrect even after successful reception
Check the settings of world time (page 24) and daylight saving time (page 44).
If the time or calendar is still incorrect after that, execute leap second reception (page 38). The leap second may be updated.
• Daylight saving time information is not contained in the satellite signal.
Leap second reception (time required: about 36 seconds - 13 minutes)
Reception to be executed when the leap second has been updated.
• You can also execute leap second setting manually. (page 52)
The OP might want to try the latter.
It's just my OCD kicking in,if my two watches didn't show the same time i wouldn't sleep at night...
It's just my OCD kicking in,if my two watches didn't show the same time i wouldn't sleep at night...
You are not alone my friend
Thanks guys, was the leap seconds quick adjustment and we're all good
maseman
You might like to bookmark and keep an eye on this page, which is maintained by the Time and Frequency Division in the Physical Measurement Laboratory at the National Institute of Standards and Technology over in the United States. That way you will be able to track the progress of DUT1 and receive ample forewarning of future leap seconds.
On the other hand...
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