What Kind of Clock is an LLM? - by Sarah Friend

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What Kind of Clock is an LLM?<br>All computational systems contain a model of time and all of them are wrong.

Sarah Friend<br>May 31, 2026

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Your laptop doesn’t keep time accurately. This may come as more or less of a surprise, depending on how much you know about operating systems. The clock certainly looks right, most of the time. It’s enough to get to your Google Meet on time. But it’s not like humans can perceive time accurately either. Once a day maybe, the laptop calls out to an NTP (Network Time Protocol) server to reorient. In between calls, it can drift. On a more machinic scale, it makes no guarantees about task processing. If that laptop were to be for example, controlling a CNC bit spinning at 3000 RPM cutting through a piece of sheet metal, or stabilizing a drone while accepting the navigational commands of a distant pilot, it would stutter. If a rogue process, maybe a defrag or cleanup task took over the CPU, the bit would slow imperceptibly, and the cut would be too short. Somewhere, a drone falls out of the sky.

Once upon a time when cell phone cameras were much worse, I worked in a machine shop<br>In systems where precise time-keeping is necessary to prevent critical failure a Real-Time Operating System, like FreeRTOS or VxWorks is used. Unlike windows, OSX, or a garden Linux varietal, real-time OS’s guarantee that tasks happen when and as they are requested with microsecond precision. If there are multiple competing tasks, the OS can manage which ones have priority between those which need real-time properties and those that don’t. Notably, this “real-time” doesn’t need to be real in the sense of the atomic clock, the computer’s clock could be inaccurate, wrong by a whole day, but it’s deterministic in that tasks happen almost exactly when they are supposed to in relation to previous tasks. The trade off is usually in less throughput and less optimized CPU utilization, but why did you come here expecting a free lunch.<br>Thanks for reading Mud and Dust! Subscribe for free to receive new posts and support my work.

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If this is unnecessarily technical and you’ve never had an interest in machine shops or the aerospace industry, surely you’ve heard of Y2K? In hindsight this may seem like it was more a media event than a software error, but the bug at its core -- theoretically writing a four-digit 2000 to a two-digit storage slot as 00 and all the various fallout that could ensue -- had a very real potential to cause problems. Did you know the default way pretty much all computers store time is as an integer that’s been going up, second by second, since January 1, 1970? At the time of this writing it’s 1779725019 o’clock. This is clearly not a system meant for human-scale timekeeping. And it may not be all that robust for machines either. Many operating systems store this as a signed 32-bit integer, with a maximum value of 2147483647. Which is to say, we’re right on track for a bigger Y2K as of January 19, 2038, at 03:14:07 UTC.<br>All computational systems contain an implicit model of time and space: time in the sense of how things are ordered and scheduled, and space in terms of how they are stored. Time specifically, the main subject of this essay, has different properties. Some of which are accuracy, how closely it’s kept to what we might call the actual objective time of the universe, approached only in a clumsy manner by humans and known perfectly only to God, maybe. Determinism, how causally and reliably one thing follows from another. Ordering, what happens before and after what else. And duration, whether elapsed time can be measured or verified. These architectural choices go on to constitute the things that can be done with the system, and, I suspect, the culture that grows around it. Conceptual models of time are a bigger force than operating systems alone, as who can forget this point from Silvia Federici, about how the watch constitutes the worker and entire pre-modern ways of time-keeping had to be eliminated as a matter of course in the project of industrialization?<br>The revival of magical beliefs is possible today because it no longer represents a social threat. The mechanization of the body is so constitutive of the individual that, at least in industrialized countries, giving space to the belief in occult forces does not jeopardize the regularity of social behavior. Astrology too can be allowed to return, with the certainty that even the most devoted consumer of astral charts will automatically consult the watch before going to work.

When Satoshi Nakamoto first circulated the release notes for Bitcoin, it was not called a blockchain, but a timechain. People have been joking that proof of work is a clock ever since -- and they’re not wrong, it’s barely a joke. Every bitcoin block is minted by a hash of its blockdata, which includes the timestamp and the hash of the previous block. Each...