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Was Y2K a real genuine threat to human existence that was averted by the blood sweat and tears of IT departments across the globe?

125 replies

OneMentalBastard · 20/09/2026 21:24

Or was it never going to be that big a deal but they all got paid loads of money for resetting computer clocks anyway?

Just curious, in light of these doomy messages about AI. Which, again, is something that only IT departments can save humanity from.

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scalt · 22/09/2026 06:55

I do think there is a wider problem of the media hyping everything up, sensationalising everything, and turning everything into a "crisis" to sell papers. It means that it can be much harder to spot the genuine threats among all the noise. Y2K was a genuine threat, but there was so much noise about it, that ever since, many people (including me) have been saying "whatever, heard it all before" when the media bang on about something; and we start wondering what they are trying to hide.

I think the genuine threats are often among what is not being talked about: the government and the media hush them up, if they are seriously worried, perhaps occasionally dropping a carefully formulated press release. There is total silence on the high fuel prices, from the government and the media, which I think could bring about massive problems, especially if they are going to creep up, penny by penny, day by day, and the authorities hope we don't notice, until the people suddenly get angry. Instead, the papers full of Earl Spencer.

And as for 2020: most of it, I couldn't take seriously at all. We had the "er, it's nothing to worry about" stage, then a swift U-turn to the "TOTAL PANIC: frighten the pants off the public" stage, and then later, "When do we deploy the variant?"
Yes, deploy the variant. Unleash the bogeyman from his cage. Crank up the fear machine. It's in the Whatsapp messages, in black and white. See also: make sure that the end of all lockdown restrictions never gets mentioned among Ukraine, monkeypox, extreme heat. Poor old Boris is still sad that he never got his big moment of saying "it is with great pleasure that I announce the end of all restriction", and he would probably have thrown in "never to return", while the scientists facepalmed.

When the government and the media are constantly playing games with our heads like this, and deliberately fucking with our minds, it is very hard to know what to seriously, and what is press noise.

GasPanic · 21/09/2026 12:55

It's impossible to know for sure.

Would it have been worse without the work done ? Yes.

Would it have been catastrophic ? Who knows. The world is a complex place and it is hard to analyse the interdependencies.

It's a bit like Brexit. Separating out the effects of COVID, the Russian-Ukraine war and the US-Iranian war is almost impossible.

Analysts basically make up stuff that generally supports their political viewpoint, but when you get into the guts of it it's actually quite hard to tell.

tesseractor · 21/09/2026 12:50

I worked on the Y2K project for an electricity company- so literally “keeping the lights on”. Though the general view was as long as the power stations could generate then the power would keep flowing - it’s basically just a wire with no computer. However if there was a problem a lot of monitoring wouldn’t have worked and it would have taken a lot longer to get power back on. And a lot more would have had to be done on the ground - less ability to reroute remotely to get sone supplies back on before actual repairs were done locally. And of course it happening in January is a time for storms etc damaging the network.

we had a lot of our customers wanting to know what we were doing to guarantee we would keep the lights on, and we did ask them what they would normally do if the power failed, as we don’t guarantee it normally. A number of businesses did look at their own contingencies as a result - and actually test eg their back up generators (not looking at some water suppliers who realised quite a large proportion didn’t work).

our old billing systems needed a lot of work - maybe less concern to our customers but we did need to get the money in to be able to pay the generators.

A few years on at another employer I couldn’t understand why the financial year was 27 on the finance system - they’d “solved” the problem by resetting the clock back to the 1920’s. It was an antiquated system, and they moved to a new system soon after.

old systems can stay in use for a long time - where I volunteer the computer system does used 4 digits for the year but if you type in just 2 digits (26 instead of 2026) it defaults to 1926 not 2026. But museums have no money for system upgrades.

MsGreying · 21/09/2026 11:56

Yes.
Well if they'd not done all the work, there would have been issues.

Some work was done on the fly after the date. This included the heating system in many tower blocks round the country. The system froze when topping credit up. Wouldn't be a problem in summer but January 1st is never a good time to have no heating.

TunnocksOrDeath · 21/09/2026 11:02

TunnocksOrDeath · 21/09/2026 07:16

Seriously? That’s the WHOLE issue. Ok, I’ll take the bait and explain it…
the Y2K issue was that in the early days of IT implementation, system memory was horribly expensive. To save on memory, many programmers had created date fields where the “year” bit literally only ran to 2 digits. It wasn’t a formatting thing where it shows 14-02-99 on screen but knows it’s actually 1999: the systems actually thought we were in the year 99.
So depending on the system, when the year goes up one from 99 the IT might either crash, because 100 requires an extra digit that didn’t exist in the code, OR it might tick round to 00 again, effectively resetting the clocks to 1900. An automated system set to calculate interest between two dates would deduct eg 15 December 1999 from 15 January 1900 and return a result somewhere in the region of minus 3,645 days interest.
The fix was to go back, check the code, Identify impacted fields, add correctly coded fields, then transfer all the data across, translating into the correct dates to store the correct year (1999 not 0099).

I of course meant about 36,470 days . I shouldn’t try mathsing while trying to eat brekky.

HowardTJMoon · 21/09/2026 10:58

notimagain · 21/09/2026 10:40

Thanks for that - As someone in the article mentions that highlights one potential problem with more modern aircraft where the increased integration of systems has the potential to cause problems that you couldn't have had 25 years back when Y2K was bothering people.

There are some advantages to the old mechanical/analogue ways of displaying info and shifting data around an aircraft, but it causes inefficiencies.

I think it's a requirement that even on aircraft with fully computerised displays they need to have a bare minimum of analogue instruments so that if all the computers go down they can still see how fast they're flying, how high they are, and what angle they're pointing.

Navigation, particularly out over the ocean, is a much harder thing to do without computers as GPS is so ubiquitous and using a sextant is not a skill that's practical in most modern aircraft.

TeenToTwenties · 21/09/2026 10:50

I was writing software at the time. We had a massive y2k project running to check all the legacy code to check dates were 4 digits not 2.
Everyone did it from trivial areas to safety critical ones. It was because the whole industry took it seriously that it turned into a non event.

VimesandhisCardboardBoots · 21/09/2026 10:45

OneMentalBastard · 21/09/2026 01:17

The government spent tens of millions on task forces and advisors. All from tech companies. Honestly I don't know if you genuinely don't remember it or maybe weren't born but these people were everywhere, very vocal and very highly paid.

And there are clear parallels with the dialogue about AI now in that individuals from private industry are taking it upon themselves to get in the public eye and get in the ear of policy makers. This is literally how the Y2K stuff started.

There are basically two different types of problem in life.

One's that are hard to identify and solve, and ones that are easy to solve, but will take a lot of effort to actually implement that solution. The first type

The millennium bug was a problem of the second type. The problem itself was trivial. Lots of software had dates in a two digit format. The year 00 was going to come after the year 99, but computers weren't going to understand that, because they just see bigger number comes after smaller number. The fix was easy, make all dates 4 digit.

As I said, the fix itself was easy. The problem was that the number of bits of code using the wrong date format were astronomical. The problem was one of effort, not of difficulty.

The hole in the Ozone layer was a similar problem that seems to have just quietly gone away. Except it didn't "just go away". It was another easy solution, that required a lot of effort. The solution was simple. Stop using CFCs. We already had other chemicals that did the job, so the difficult bit was mostly a case of effort, changing manufacturing processes, and governments convincing companies that they needed to do so.

Simple solution, easy but time consuming fix. In both of the above cases, there was an obvious deadline as well. With the millennium bug, it was an actual date. With the ozone layer, there was a great big stonking hole we could see with the right equipment, obviously getting bigger.

AI is a more nebulous threat. The actual risk isn't clearly defined. And the solution certainly isn't. There's no "Stop using CFCs", or "change every date to 4 digits" here. We could stop making and using AI, but that's never going to happen, there's too many rich people too heavily invested in it. Noone had a vested interest in the millennium bug happening. Noone was going to make money from it (aside from in the effort of fixing it). However, a lot of people have a lot of money invested in AI continuing to be a thing.

Do I think AI is going to take over the world or kill all humans? Not particularly. But the problem itself is a very different beast to the Milennium bug. For a start, we haven't even really defined the problem yet.

notimagain · 21/09/2026 10:40

HowardTJMoon · 21/09/2026 10:27

For an example of what can happen to aircraft when there's a time-related bug in their software, this makes an interesting story

https://www.defenseindustrydaily.com/f22-squadron-shot-down-by-the-international-date-line-03087/

TL;DR - the navigation software on F22 fighter jets crashed in flight when crossing the international dateline and couldn't be restarted. They were far out over the ocean and If there hadn't been a tanker aircraft there for them to follow back to base then they could have been in real trouble.

Thanks for that - As someone in the article mentions that highlights one potential problem with more modern aircraft where the increased integration of systems has the potential to cause problems that you couldn't have had 25 years back when Y2K was bothering people.

There are some advantages to the old mechanical/analogue ways of displaying info and shifting data around an aircraft, but it causes inefficiencies.

HowardTJMoon · 21/09/2026 10:27

For an example of what can happen to aircraft when there's a time-related bug in their software, this makes an interesting story

https://www.defenseindustrydaily.com/f22-squadron-shot-down-by-the-international-date-line-03087/

TL;DR - the navigation software on F22 fighter jets crashed in flight when crossing the international dateline and couldn't be restarted. They were far out over the ocean and If there hadn't been a tanker aircraft there for them to follow back to base then they could have been in real trouble.

sashh · 21/09/2026 10:22

notimagain · 21/09/2026 06:13

The aircraft actually falling out of the sky predictions were nonsense.

Worse case was either a failure of some of the navigation systems (and there were workarounds for that, in place from way back to cope with common or garden system failures that occasionally happened anyway) and maybe probs with ATC (and there were work arounds for that).

As it happened due to all the hardwork done by the IT experts the clock ticked over with no hiccups.

It also helped that software updates on planes used floppy disks. Actually quite a lot still do.

AtBeaverGoat · 21/09/2026 09:55

OneMentalBastard · 20/09/2026 21:25

I thought all the planes were going to drop out of the sky. But they didn't.

No , but AI will probably kill us all

TorroFerney · 21/09/2026 07:20

I had a lovely holiday in Israel in the January with my y2k overtime. And I wasn’t even in it, I worked in the customer side of financial services so we tested it all still worked.

MaryBeardsShoes · 21/09/2026 07:18

@PrizedPickledPopcorn “I really resent the way you read my post and made assumptions rather than wondering what I actually meant, given that you didn’t understand it.”

I didn’t misunderstand you. You weren’t clear. But actually a bomb designed to kill 100s of thousands of people, did do that exact thing. So, cry me a river (regarding your resentment).

TunnocksOrDeath · 21/09/2026 07:16

GaryLurcher19 · 21/09/2026 02:48

Why would a bank take any interest from a savings account rather than adding it?

Why would a system governed by a clock fail to understand that 2000 is one increment on 1999?

Seriously? That’s the WHOLE issue. Ok, I’ll take the bait and explain it…
the Y2K issue was that in the early days of IT implementation, system memory was horribly expensive. To save on memory, many programmers had created date fields where the “year” bit literally only ran to 2 digits. It wasn’t a formatting thing where it shows 14-02-99 on screen but knows it’s actually 1999: the systems actually thought we were in the year 99.
So depending on the system, when the year goes up one from 99 the IT might either crash, because 100 requires an extra digit that didn’t exist in the code, OR it might tick round to 00 again, effectively resetting the clocks to 1900. An automated system set to calculate interest between two dates would deduct eg 15 December 1999 from 15 January 1900 and return a result somewhere in the region of minus 3,645 days interest.
The fix was to go back, check the code, Identify impacted fields, add correctly coded fields, then transfer all the data across, translating into the correct dates to store the correct year (1999 not 0099).

notimagain · 21/09/2026 06:13

KnickerlessParsons · 20/09/2026 23:27

That’s because a
lot of people worked very hard to make sure they didn’t.

The aircraft actually falling out of the sky predictions were nonsense.

Worse case was either a failure of some of the navigation systems (and there were workarounds for that, in place from way back to cope with common or garden system failures that occasionally happened anyway) and maybe probs with ATC (and there were work arounds for that).

As it happened due to all the hardwork done by the IT experts the clock ticked over with no hiccups.

Maray1967 · 21/09/2026 06:10

TheBossOfMe · 20/09/2026 21:36

No they didn’t. Because lots of people worked for years to make sure that wasn’t going to happen.

Absolutely. It enrages my DH when people cast doubt on what was necessary - he worked hours of very necessary overtime. In his case it wasn’t as crucial as air traffic control, but a major retailer would have stopped being able to trade without his and his colleagues’ work.

thetruthshallsetyoufreebutfirstitwillpissyouoff · 21/09/2026 05:52

Out of interest OP, do you feel the same about security spending? Millions (probably billions, idk the figure) is spent on MI5 every year so they can prevent terrorist attacks. We don't see the results of this as the attacks don't happen because they stopped them. Doesn't mean the threat isn't there.

I do have a genuine, non-snarky, question for those who worked on Y2K though - what did you actually do to fix the bug? I kind of get if it was on a computer but video machines - how were they affected? Explain it to me like I'm 5 (genuinely, I don't disbelieve in the issue, I just don't understand it). Secondly, can you recommend any few learning resources for a time-poor mum as I think this, and AI works is something I need to get my head around.

sashh · 21/09/2026 04:05

OneMentalBastard · 20/09/2026 22:38

So you know the people who stopped the planes crashing? Because - and this is wild - absolutely none of them did. Years and years we'd been told it would happen, and then it didn't.

Those plane IT people must have worked ever so hard.

You might be surprised at how old the software in aviation is.

Something can be simple once you get to it, but getting there can be difficult.

It's simple to switch a light switch on, but if the switch is under a pile of rubble it's a bit more complicated.

GarlicSomething · 21/09/2026 03:09

GaryLurcher19 · 21/09/2026 02:48

Why would a bank take any interest from a savings account rather than adding it?

Why would a system governed by a clock fail to understand that 2000 is one increment on 1999?

An automated banking system would reckon the current date as 100 years ago. It would obviously calculate that you'd been overpaid interest. Some might even deduce that you had no money in your account and take the whole lot back, since they weren't set up to recognise deposits made in the future.

Because they were only programmed with DD/MM/YY, not /YYYY.

PleaseDontTreadOnTheDaisies · 21/09/2026 03:03

I think the issue was that computer systems (from the 1970s, when the next century was way off) would revert back to 1900 instead of onto 2000. Computers then only knew of a year beginning 19.. - they could not compute a year beginning 20.. because they'd never been told to. The '19' was a given in computer systems then, it simply hadn't been programmed to go onto 2000. Until Y2K compliance of course.

GarlicSomething · 21/09/2026 02:59

GaryLurcher19 · 21/09/2026 02:36

Can anyone explain why it was going to happen? I never got that.

In short, a whole bunch of machines and software had been programmed to work with dates in the DD/MM/YY format. This meant that, when they were given a year ending 00, they'd read it as if it was 1900.

This obviously meant that everything that had anything to do with times & dates would fuck up. Pretty much all computers and programs rely on them. There were knock-on complications, where systems suffering a data overspill from trying to handle dates that didn't make sense would shut down.

You can imagine an air traffic control system tracking flights on 31st December 1999, which calculated their next positions as occurring on 1st January 1900! Given the systems aren't set up to monitor time travel, they wouldn't be able to process the information.

GaryLurcher19 · 21/09/2026 02:48

TunnocksOrDeath · 21/09/2026 00:02

I imagine that if your bank had taken 100 years' worth of interest from your savings account in Jan2000 instead of crediting it with one month's, you might have been a bit cheesed off.
Having spent over a decade in Finance IT, I can tell you that there is rarely "a" system. It will be a patchwork of systems developed over time, and a change to any one of them requires the whole flow for any impacted transaction type to be robustly regression tested. Identifying all the instances of dodgy date coding and fixing them in a way that ensures that only compatible data is passed between systems in the meantime is very fiddly, time consuming and expensive.

Why would a bank take any interest from a savings account rather than adding it?

Why would a system governed by a clock fail to understand that 2000 is one increment on 1999?

GaryLurcher19 · 21/09/2026 02:36

Thecows · 20/09/2026 21:38

You can't think why that didn't happen then?

Can anyone explain why it was going to happen? I never got that.

PleaseDontTreadOnTheDaisies · 21/09/2026 01:45

OneMentalBastard · 21/09/2026 01:17

The government spent tens of millions on task forces and advisors. All from tech companies. Honestly I don't know if you genuinely don't remember it or maybe weren't born but these people were everywhere, very vocal and very highly paid.

And there are clear parallels with the dialogue about AI now in that individuals from private industry are taking it upon themselves to get in the public eye and get in the ear of policy makers. This is literally how the Y2K stuff started.

I don't really know what you're trying to argue here OP. The clear parallels are that AI needs government interventions and controls, just as Y2K compliance did.
You're not comparing like with like - AI now is a on a whole different level. Working for Y2K compliance was not a job creation scheme for techies, and nor is the argument for controlling AI.
Y2K Compliance was a reaction to a specific event in the future - ie. the century changing from 19.. to 20..
AI is a growing technical revolution, the like of which we've never seen before. Multiple tech companies from multiple different countries, are racing to develop an AI super intelligence which will surpass human intelligence.
If you want to believe that this is not genuinely a potential risk to humanity, then that's up to you, but several whistleblowers have sounded the alarm on this (one refused a $2M settlement figure to stay silent.) This goes beyond sensationalist reporting.