The change in year has caused a few issues Dmitrii_Guzhanin/Getty

Parking meters, cash registers and a professional wrestling video game have fallen foul of a computer glitch related to the Y2K bug.

The Y2020 bug, which has taken many payment and computer systems offline, is a long-lingering side effect of attempts to fix the Y2K, or millennium bug.

Both stem from the way computers store dates. Many older systems express years using two numbers – 98, for instance, for 1998 – in an effort to save memory. The Y2K bug was a fear that computers would treat 00 as 1900, rather than 2000.


Programmers wanting to avoid the Y2K bug had two broad options: entirely rewrite their code, or adopt a quick fix called “windowing”, which would treat all dates from 00 to 20, as from the 2000s, rather than the 1900s. An estimated 80 per cent of computers fixed in 1999 used the quicker, cheaper option.

“Windowing, even during Y2K, was the worst of all possible solutions because it kicked the problem down the road,” says Dylan Mulvin at the London School of Economics.

Coders chose 1920 to 2020 as the standard window because of the significance of the midpoint, 1970. “Many programming languages and systems handle dates and times as seconds from 1970/01/01, also called Unix time,” says Tatsuhiko Miyagawa, an engineer at cloud platform provider Fastly.

Unix is a widely used operating system in a variety of industries, and this “epoch time” is seen as a standard.

The theory was that these windowed systems would be outmoded by the time 2020 arrived, but many are still hanging on and in some cases the issue had been forgotten.

“Fixing bugs in old legacy systems is a nightmare: it’s spaghetti and nobody who wrote it is still around,” says Paul Lomax, who handled the Y2K bug for Vodafone. “Clearly they assumed their systems would be long out of use by 2020. Much as those in the 60s didn’t think their code would still be around in the year 2000.”

Those systems that used the quick fix have now reached the end of that window, and have rolled back to 1920. Utility company bills have reportedly been produced with the erroneous date 1920, while tens of thousands of parking meters in New York City have declined credit card transactions because of the date glitch.

Read more: How tech bugs could be killing thousands in our hospitals

Thousands of cash registers manufactured by Polish firm Novitus have been unable to print receipts due to a glitch in the register’s clock. The company is attempting to fix the machines.

WWE 2K20, a professional wrestling video game, also stopped working at midnight on 1 January 2020. Within 24 hours, the game’s developers, 2K, issued a downloadable fix.

Another piece of software, Splunk, which ironically looks for errors in computer systems, was found to be vulnerable to the Y2020 bug in November. The company rolled out a fix to users the same week – which include 92 of the Fortune 100, the top 100 companies in the US.

Some hardware and software glitches have been incorrectly attributed to the bug. One healthcare professional claimed Y2020 hit a system developed by McKesson, which produces software for hospitals. A spokesperson for McKesson told New Scientist the firm was unaware of any outage tied to Y2020.

Exactly how long these Y2020 fixes will last is unknown, as companies haven’t disclosed details about them. If the window has simply been pushed back again, we can expect to see the same error crop up.

Another date storage problem also faces us in the year 2038. The issue again stems from Unix’s epoch time: the data is stored as a 32-bit integer, which will run out of capacity at 3.14 am on 19 January 2038.