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It's time to mentally prepare yourselves for this (lemmy.world)

submitted 7 months ago by The_Picard_Maneuver@lemmy.world to c/programmer_humor@programming.dev

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[-] NeatNit@discuss.tchncs.de 40 points 7 months ago

The proposed time zone is to drift about 1 second every 50 years. I also suspect it wouldn't really be a time zone in the same sense as the time zones we know - it would just be a standardised calibration reference. Dates and times expressed in "moon time" would probably just be some leap second off of a known Earth time zone, and because it's mere seconds over centuries, I think the only use of this time zone is to calculate ultra-precise time diffs between two earth datetimes when the observer is on the moon. At least, that's how I interpret the articles I can find about it.

[-] ricecake@sh.itjust.works 12 points 7 months ago

It's also important for things like GPS, as related to other planets, as well as orbital maneuvering.

What they're actually being told to build is "write down the rules for moon time", which is basically what you said but defined in terms of "this much faster than earth time", and a system doing the same thing on other planets or places in the solar system.

So it's less a timezone and more a time system, and instructions for how you calibrate your atomic clock on the moon and reconcile the difference with terrestrial clocks.

[-] JasonDJ@lemmy.zip 4 points 7 months ago

Serious question....why would an entirely isolated GPS constellation need to have "a time zone" as opposed to it's own epoch (like unix)? It's on the receiver side that all the computation happens, aren't the satellites essentially just announcing an agreed-upon time? Wouldn't the client be able to do it's own comparison of "it's time", as long as it's source of time is also synchronized with the constellation?

[-] ricecake@sh.itjust.works 1 points 7 months ago

I believe, and we're at the edge of my understanding here, that the satellites need a consistent adjustment for local relativity. Because the satellites also have their clocks tick differently.
So they define a new time standard for the moon so that lunar operations can function based on that time standard, rather than having to recalculate relative to earth.

https://arxiv.org/abs/2402.11150

That's the paper from NIST that's basically the timezone part of it all.
They're basically defining how to calibrate moon clocks so we all agree exactly how they differ from earth clocks.