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Comment by runnr_az | Hacker News Reader

As an Arizona resident, my recent Honda CRV's clock is off by an hour for half the year. Since usually the carplay display overrides the clock, it's no big deal, but it cracks me up that, despite being a professional programmer, I have yet to figure out how to set it correctly

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The difficulty of setting a VCR's clock was a meme in the 1990s, and I can attest, justifiably so.

But at least it was possible. The clock setting being impossible without a proprietary and easily lost or destroyed SD card is pretty good, but we can do better. It could be just impossible to fix a wrong clock. Truly that would be the apotheosis of user unfriendly design.

My very technical and hands on father used to have us set the VCR clock, the controls were in a tiny compartment under a flap that required either small fingers, or very careful manipulation with the point of a protractor or something.

We went from difficult to manipulate buttons through to multi-function buttons where controls get hidden through some incomprehensible maze of menu options, to now where it sometimes feels lucky if you even get an option to manually set the time at all.

I'm reminded of an old commercial depicting kids taunting another kid by asking "What time is it at Billy's house? 12 O'Clock! 12 O'Clock! 12 O'Clock!" Might have been a Blockbuster commercial? I can't remember.

The Internet Helpdesk sketch, by Three Dead Trolls In A Baggie, had the helpdesk guy describe the hapless user he's trying to help as a "12 o'clock flasher". "You know, every appliance in his house is always flashing 12:00".

P.S. Found the video: https://www.youtube.com/watch?v=k7FYR72mr0E

Oh man, this reminds me of an episode of a show I watched when I was a kid in the 90s, where the running joke was all the characters, at different points, saying something like "I tried setting up the VCR to record it, but every time I press the button the number 12:00 starts flashing on the screen and I panic." I haven't been able to find it again. I think it was https://en.wikipedia.org/wiki/Mother_Goose_and_Grimm_(TV_ser...

In 1974 when I was an medical intern at Los Angeles County-University of Southern California Hospital, ALL the round analog wall clocks with hands in all 26 operating rooms were correct six months a year: there was NO provision for automatically advancing/moving them back when DST started/ended, nor did anyone do it manually.

I was told by our school electrician that long ago the clocks were adjusted by the power company. So around 2am DST they would either send power at 59Hz* to fall back or 61Hz* to spring forward. This was from the era when power grids were separate and analog. With newer national grid-tie it might not even be possible to do now.

> I was told by our school electrician that long ago the clocks were adjusted by the power company. So around 2am DST they would either send power at 59Hz* to fall back or 61Hz* to spring forward. This was from the era when power grids were separate and analog.

That wouldn't have worked.

Grid-tied synchronous clocks (https://en.wikipedia.org/wiki/Electric_clock) were once ubiquitous and did derive their timekeeping stability from the grid frequency, but that is only suitable for keeping time once set. It works because electric grids are frequency-controlled and stabilized, where deviations from the reference frequency are corrected over long intervals.

In principle you could send power at 59 or 61Hz to adjust these clocks, but there are two problems:

1. The grid frequency isn't arbitrary, it's also directly coupled to the rotary inertia of every turbine that powers the grid. This is why power fluctuations cause frequency changes: temporary oversupply or undersupply causes these turbines to slow down or speed up respectively, using their inertia as power storage. Potentially screwing up every other piece of mechanical equipment tied to the grid for the sake of clock changes is... a poor optimization.

2. A one-Hertz difference isn't enough to change the clocks in a timely way. To change time by an hour you need to gain or lose 3600 * 60 = 216k cycles, but a 1Hz change gains or loses one cycle per second. It'd take about 2.5 days to complete a one-hour change via this mechanism.

I don’t know about that, but I was told by someone who worked at a power generation plant in the 1970s that they had a clock in the plant, that they would compare to the time broadcast on the radio frequency that carried the official time, and any time it diverged they would slightly adjust the frequency of the alternating current until it matched.

I was a kid but I do know the clocks in my elementary, middle, and high school were accurate. Near end of day, we would impatiently stare at the clock waiting for the release bell. Being a public school, the clocks were bolted securely to the wall. Being little shits, students would probably steal them if they could, LOL. So how did they keep 100s of clocks on time? I asked and was told by the school maintenance that it was done through power.

https://en.wikipedia.org/wiki/Master_clock

I remember in my elementary school the clocks were all synchronized to a system somewhere, presumably in the head office. The day after going back to school after a DST change the clocks would all be off by an hour and sometime in that morning they would all suddenly freeze, then fast forward or rewind an hour and then restart. In retrospect it is amusing that whomever was in charge of updating the clocks didn't do it when they first got in but waited until the school day had started.

It's crazy they didn't have a centralized clock system in a facility like that. What a thing to scrimp on.

What are the odds they did have a centralized system for setting the clocks, but nobody knew how to operate it or cared enough to find out? Maybe someone set a password and then lost it. And of course if you have a centralized system it means you can't manually fix the individual clocks.

I'd laugh whenever I looked up and saw the wrong time....

I worked in a Network Operations Center in the early 1990s, and there was a large projection display with four other monitors around it. Across the top were four round analog clocks, representing the time zones of the United States. I was one of four operators, all in our 20s.

So, Daylight Savings Time ended, and the early-morning operator had all the clocks set by the time I arrived, and the third operator came in, looked at them, and said "Great! So, did you take all four of them down and adjust the time individually?" "Yeah" "Didn't think about taking one off the end, adjusting it, and moving the others down the row?" *facepalm*

Being a professional programmer, set it to UTC once and be done with it!

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