Geeky, Technical Regarding The Atomic Range

Bizzle

New Member
Hi all, have a question about the Atomic range of G-Shocks.

As I understand it, the Atomic models receive signals from one of six atomic clocks. Presumably, the time given by these clocks is International Atomic Time (TAI), adjusted for your timezone.

But! Atomic Time isn't what we generally use to measure time on earth. That's UTC, or Coordinated Universal Time, which is based on the length of the earth's rotation and has had leap seconds inserted into it (the same as February 29th in a leap year) and over the years has become 35 seconds 'slower' ('behind' is probably a better word) than International Atomic Time.

Still with me, or have you all fallen asleep?! My question is which of these two standards is used by the Atomic models? Judging by the name, you'd assume TAI, but to me that's the 'wrong' time.

I know, I know, it's only 35 seconds but there's lots I can do in 35 seconds. Sometimes twice.

If anyone can shed any light on this I'd be really grateful
 

rutteger

Administrator
Welcome to the site :)

I always assumed the Gs sync to UTC, since this is what everyone uses as 'the time'. Also I know my atomic Gs have the same time as my PC which is sync'd via NTP - apparently NTP uses UTC so think that seals it?
 

Bizzle

New Member
Yep, NTP uses UTC so I'm pretty sure you're right. I guess they take the TAI time and minus 35 seconds....although how do they tell it to do that? How does the watch know that another leap second has happened?

Hmmmmmm.....

Edit: Thinking logically, I guess the Atomic site must broadcast the time in UTC, it would be very simple for them to do that.

This is bad news for my wallet
 

rutteger

Administrator
What price accuracy though ;)

The watch syncs once a day, assume the radio station just broadcasts UTC so it's simple enough to add leap seconds as required.
 
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