Threadlines: The Computer Glitch that Threatened the World

Programming Note:

This article is best consumed as the video essay I published covering the same topic, but enhanced with compelling visuals and audio.

Click the link below to watch.

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Now for the article:

The Year 2000 Problem

It’s 1995 - everyone is talking about the OJ Simpson trial, Friends was on it’s second season, and Coolio’s Gangsta’s Paradise was the hit song of the year.

Our story starts in Michigan, as some customers shop at an upscale grocer, the Produce Palace.
They completed their regular shopping, carts full with  milk, bread and eggs, and walked to the check out aisle. However, after handing over their credit cards to the checkout attendants, the cash register promptly glitched out. 

“Okay, no big deal” they thought - “just restart the register computer and try again.” 

But the credit cards glitched out the register again, and again.

They look around the grocery store and realize that this is happening to everyone. Every register is broken. The checkout lines are building up. Hours later, the computers are still not functioning, and people are angrily leaving without their groceries.

This was a nightmare.
And it can all be traced back to one small software bug. 

In the early days of programming, computer memory was expensive, and therefore it was incumbent upon programmers to minimize usage of memory wherever possible. 

One of the ways that early code was written to save space was processing dates as the only last two numbers of the date. 

Since computers only gained wide usage in the 20th century, programs could simply cut the "19" from the year of a date, allowing them to only store the last two digits of the year instead of four. 

So - “97” for 1997.

Only cutting out two numbers might not seem like a lot, but multiply these kilobytes over larger and larger data files, and it starts to add up. So, this did accomplish the goal of saving memory, but, it had an unfortunate consequence; this code would not correctly process dates after 1999. For instance, it would process the date 2000 as “00” - which also could be 1900. Or 1800. Or whatever.  

So back to the Produce Palace, and our stuck grocery shoppers. Many customers had just received new credit cards or renewed their old ones. These new credit cards had an expiration date in year 2000, which was only a few years away. This couldn’t be that big of a deal. But the code in the cash registers was processing this as an expiration of 1900, and it was ruining them, leading to issues ranging from failing modems to corrupted records. 

This glitch was causing the Product Palace to lose business as grocers didn’t want to shop there if they were just as likely to get stuck in hour long lines as technicians tried to fix the registers again and again. 

The Product Palace took the manufacturer of the registers to court after a reported 105 separate occurrences of this computer defect, and led to an eventual settlement of a payment of $260,000.

But, this was far from the last time that the world would hear about this software bug. 

In the years following the Product Palace cash register issues and leading up to the turn of the millennia in 2000, fear of this bug ran rampant. It was quickly a common belief that as computers everywhere switched to a date in the 2000s, they would begin to fail, and that would lead to widespread, catastrophic effects.

But… it’s 2024 and we are all still here, and computers are more ubiquitous than ever. So, what happened? Let’s look into it.

Noticing the Problem

In September of 1993, Computerworld magazine published its weekly article. Buried deep on page 105 of the issue was an article by computer consultant, Peter de Jager. He wrote:

Yeesh. Worse than a car crash. That does not sound good. 

And this article happened to get the attention of folks in the technology world. People began to take notice of the fact that “hey, we probably haven’t thought about this whole date thing. This could actually hurt our computer systems.” 

This was also perfectly coinciding with a time in history when computers were rapidly moving from technology relegated to back rooms to technology that every single person interacted with on a regular basis. 

The 1990s saw the introduction of the iMac, of Windows 95, of Mosaic, the first internet browser, the proliferation of video games, and much more.

The lessons of Y2K, 20 years later - The Washington Post

So, at the same time that people are starting to use computers much more often, de Jager warned us in what has now been called “the information-age equivalent of the midnight ride of Paul Revere” - that those same computers are probably about to start crashing once the millennium flips. And so, the world began to take notice.

Y2K Gains Traction

In 1995, David Eddy was in a conversation with fellow tech-savvy “computer geeks” discussing the potential code glitch as identified by de Jager. During this chat, he used the numeronym of “Y2K” to refer to the glitch as a more streamlined way to describe the glitch. In this term, “Y” = year and 2K 2 kilo, or more nicely, 2000 - it was an effective way to refer to the bug, and it caught on.

So, now we have a simple term for the code problem, and the tech world is becoming more and more aware of the potential issue.
It was at this time that concerned individuals began to brainstorm potential impacts. 

If a cash register could get bricked by a credit card expiration date, what else could happen?

When more date fields are updated to ‘2000’, could that cause glitches in software programs with a more widespread impact? What about telephones? The banks? National defense systems? 

Taking that even further, could these glitches lead to more severe, real-world impacts? Could airplane computer systems crash mid-flight? Could power grids glitch out, and plunge thousands into a world without electricity? Could nuclear weapons be mistakenly launched?  

As the months passed and we crept closer to January 1, 2000, these fears began to feel more and more real. 

In 1996, Senator Daniel Moynihan wrote to President Clinton warning that “each line of computer code needs to be analyzed and either passed on or be rewritten. The computer has been a blessing; if we don’t act quickly, however, it could become the curse of the age.”

And so, efforts to fix the “Y2K bug” began in earnest.

Trying to Fix Y2K

In the roughly 4 years between Moynihan’s call to action and December 31, 1999, billions of dollars, with estimates ranging from $100 billion to $500 billion were spent on efforts to fix Y2K.

Computer programmers worldwide examined the code across any context they could think of. Starting with the most critical systems that would cripple society if they fell - healthcare, financial, utilities - teams across the world checked and rewrote - at least millions, if not billions, of lines of code. 

One programmer tells his story of being hired by a satellite TV company to comb through their code and correct any potential Y2K bugs. He reports that he alone searched through "hundreds of thousands of lines of code, almost all of it in C", finding and fixing "dozens of issues, in dozens of different applications." 

Moreover, remediation was not limited to specific programmers. In the US, Clinton launched a full-fledged council dedicated to addressing concerns with Y2K. Internationally, the World Bank launched the International Y2K Cooperation Center which worked to help countries across the globe prepare for Y2K.

Zachary Loeb reported that “best practices and solutions were liberally shared between the government and businesses, and carefully constructed contingency plans were put in place just in case the bug was still lurking in some systems.”

Simply put, if you were someone with the means and/or ability to help fix Y2K bugs, you were likely to be contracted to do so. 

Altogether, this was a spectacular show of cross-country, cross-ideology, and cross-politics collaboration, as experts, businesses, and governments determined that some simple date processing bug would not lead to widespread chaos. 

Approaching Y2K 

For years, fears about Y2K were mostly limited to tech circles - programmers and tech-conscious folks. But, the awareness gradually expanded and ramped up leading up to the turn of millennia.

In 1999, Time Magazine and CNN conducted a poll to understand the public’s level of concern about the bug, and they found that “59 percent of respondents were either ‘somewhat’ or “very concerned” in regards to the ‘Y2K bug problem.’”

These fears were directly reflected by the public’s preparations for the dreaded New Year's Day.
As January 1, 2000 approached, people began hoarding supplies like food, generators, water, kerosene heaters, and cash in preparation for potential worst-case scenarios. 

In 1999, the Washington Post reported on a Home Depot in Alexandria, Virginia that had created “a giant promotional center in front of the store that includes batteries of every size, while generators, flashlights and packaged fireplace logs are stacked by checkout lanes.”

The year 2000 arrived, and the world held its breath. 

January 1 came and went. 

Everything was okay. 

Trains did not derail, water still flowed into people’s houses, and computers still functioned. 

There were some Y2K issues, but most were similar in scale and scope to the Produce Palace cash registers - more annoying than truly harmful.

Some of the more amusing issues from Y2K included a US man being issued a $90,000+ fine for a video that was listed as 100 years overdue, a Denmark newborn being registered as 100 years old at birth, and a German man having over $6 million credited to his bank account on December 30th, 1899. 

Certainly, the Y2K date rollover had some detrimental effects. They were just nowhere near the scale and severity that would cause the feared effects of hunger, war, or societal collapse.

Y2K Didn’t Cause the Downfall of Society

Now, let’s refocus on the 1993 author of one of the original articles calling attention to this potential issue - Peter de Jager.

After years of remediations undergone by programmers around the world, de Jager was utterly convinced that the Y2K bug had been defeated.

In fact, he was so convinced that he chose to spend the New Year’s rollover sitting on a flight flying to London. De Jager explained that he was trying to make a statement here, stating, "How do you prove that you truly believe that without doing something like this? I had absolutely no concerns at any point during the flight. I knew that we would come through it, in the same way I knew that we would not have power failures and that the telephone systems would work."

De Jager and his predictions were fully correct. 

Whether it was the years and billions of dollars that the world spent addressing Y2K or if it was just never a big problem to begin with, the incredible downfall threatened by Y2K never materialized.

Y2K believers will hold tight to vindication, emphasizing that the only reason we didn’t see the chaos was because we spent years rewriting the code. 

Y2K skeptics would allege that we never needed to spend the money and time rewriting codes and that it was all simple fearmongering.

Whatever the case, the world chose to be safe rather than sorry. And we shouldn’t have any regrets about that. 

Y2K Today

The Y2K scare persists today as a cautionary tale about the potential pitfalls of technological dependence. While the potential meltdown never materialized, it was not entirely unfounded.

The Y2K scare exposed the vulnerability of our increasingly computer-reliant world. 

It serves as a stark reminder of our growing dependence on complex computer systems and the potential consequences when those systems malfunction. 

Technology has become deeply ingrained in modern society. From power grids and financial institutions to transportation and communication networks, the potential for widespread disruption due to a software bug is scary. 

As our reliance on technology continues to grow, new systems and interconnectedness lead to ever-more complex dependencies. The spread of misinformation, corporate surveillance, biased algorithms, and data breaches plague our modern, highly digital world. 

We must be vigilant to build systems and practices - both in our personal lives and at a societal level - that use technology as a tool without becoming fully reliant on it. 

In essence, Y2K serves as a reminder of the power and fragility of our technologically driven world.

In 2024, the public can look back at Y2K with a combination of relief and amusement. Relief that there was no widespread chaos, as was predicted, and amusement that we as a society were so concerned about a code glitch that we began pulling tons of cash out of the banks. 

Let us hope that we never have to consider fears of this magnitude again.