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Atomic clock vs my computer


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Since I just got a circa an early 1990s Longines VHP I've started tracking it to the image of a clock on the NIST Atomic clock site.  I was shocked to see my watch had lost and gained few seconds over 5 days. So today I compared it again and it was -2.74 s. Then I looked more closely at the NIST numerical clock and  image of the clock below it.  They were different, and the clock image was -2.74 and stated "your device's clock is off by 2.74 s". I never imagined the clock image was representing my varying computer clock. Bottom line it it was a relief to learn my watch is right on time and my computer clock varies. Thought I would post this in case others are looking at NIST clock like I did.

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Henryr

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I often wonder just how precise time needs to be,I have around 80 watches, and thirty clocks and can say that the old adage is very true if you own a clock you know the time if you own more than one you are never quite sure :fpc:

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Inaccurate time on PC is due to poor OS implementation which uses a single time server, often also inexact like time.windows.com. Below an article on how to change this setting to a better one, like e.g. uk.pool.ntp.org if you're in the UK, or replace uk with your country code. Doing that I have about 0.3 sec difference with the NIST web page, and that is very normal because of the delay between said USA server and a PC in e.g. Europe.

https://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings/how-to-force-windows-10-time-to-synch-with-a-time/20f3b546-af38-42fb-a2d0-d4df13cc8f43

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This is very evident when trying to purchase from eBay. You're down to the last few seconds and you place a bid at the last 2 seconds and 5 others bid and you miss out. Turns out there were a couple extra seconds because your computer time and the time on the eBay servers was different. Annoying!

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