Earth's moon is getting its own time zone

[Purplecat]

@nosaj

With all the network and data complexity, people are usually surprised when I tell them that my biggest single problem is time stamps and time zones.

Oblig. Video

The Problem with Time & Timezones - Computerphile

[bucaneer]

This is not about creating a time zone, but a time standard. That 58-ish microseconds per day relativistic difference in time is the entire reason for the project. UTC is based on International Atomic Time, which is an average reading of hundreds of atomic clocks placed around the surface of the Earth. LTC will have to be based on the readings of atomic clocks on the surface of the Moon in order to establish a consensus standard in that relativistic frame of reference. For practical reasons, the system will also have to keep track of offsets from UTC so that any given timestamp could be converted between UTC and LTC in a standardized way. The same principle could be applied to other planets and moons if needed.

As noted in the Celestial Time Standardization memo, having a time standard that is accurate to your frame of reference is useful if you want to have something like GPS navigation, or to calibrate instruments that rely on the definition of the SI second, e.g. a laser range finder:

Additionally, the navigation accuracy a system can achieve with signals from multiple space-based assets, such as a person navigating on Earth with signals from Global Positioning System satellites, depends on the synchronization of those assets with each other. At the Moon, synchronizing each lunar asset with an Earth-based time standard is difficult — due to relativistic effects, events that appear simultaneous at the Earth (e.g., the start of a broadcast signal) are not simultaneous to an observer at the Moon.

Beyond these operational challenges, the direct use of UTC at the Moon (i.e., without correction) as the local time scale would have cascading effects for applications that require precise metrology. International System of Units (SI) core unit definitions, including the meter and kilogram, rely on the SI definition of time. Due to relativistic effects, a non-SI unit would introduce uncertainty in core unit definitions. These types of errors will have undesired impacts, such as reducing the accuracy of mapping and inertial navigation products. Defining a local time scale can provide a stable reference point for these base units and conversions that must be independently realized on the surface of the Moon.

[Flanker7]

More detailed article here: https://www.cnn.com/2024/05/30/science/lunar-time-zone-scale-nasa-artemis-scn/index.html - covers the atomic vs crystal and time-zone issues that I didn’t post yesterday.

[FGD135]

What time is it on the moon? China and the US are racing to decide

[Flanker7]

China can’t build a submarine that floats, so “No thanks!” on that one

[Otherbrother]

@the_borderer

Just change it from Anywhere on Earth to Anywhere in the Universe. By the time that becomes a problem for us we’ll have moved on to stardates or something.

One thing that I appreciated on Babylon 5 but was very rarely brought up in Star Trek is the fact that time zones exist and you really should take that into consideration before calling people up. But I like to think that Robot Chicken’s explanation is the right one: they just have a night shift that has their own series of adventures.

Robot Chicken - Star Trek: The Next Generation's Night Crew

[gatto]

the night shift existed on tng. usually data was the senior officer on the bridge for those

Duty shift

[Gyrofrog]

Negativland - "Time Zones"

[FloridaManJefe]

man, i scrolled all the way down to find that.
not disappoint.

[smulder]

@bucaneer

This is not about creating a time zone, but a time standard

… there would be less confusion about these things if the scientific time unit was not supposed to also coincidentally be a specific fraction of a solar day

They should really define an S.I. “moment” (or something) as exactly 10¹⁰ cesium transitions and stop talking about “seconds” at all

[chenille]

Since you’d have to redefine the derived units too, maybe we can just call them Avoirdupois seconds, hertz, newtons, joules, and so on to prevent any confusion.

[smulder]

… the most annoying part of the metric system is having to learn French