Your GPS devices may stop working this week, because the date will roll back to zero.
If that sounds familiar, it’s because the situation is basically the same as the “millennium bug” behind the infamous Y2K scare. Thankfully, no one is hyping the GPS bug to an exaggerated degree — but it could still cause problems.
Basically, the rollover will occur because of the way that the Global Position System network timestamps its data.
The timestamp field that contains the week is a 10-bit binary number. That means it can only account for weeks between zero and 1,023. That limits the system to 1,024 total weeks. After that, the timestamp will roll back to zero and start counting up to 1,023 again.
This, thankfully, is expected behavior and most manufacturers have prepared for it. But the amount of critical systems that use GPS data does make the situation a bit hairy.
It’s not just your household GPS devices that could be affected. Important systems like power grids, emergency services, financial markets, and industrial control computers also rely on GPS data.
According to testing by the U.S. Department of Homeland Security, there’s a chance that some GPS data receivers could be negatively impacted by this.
Some devices could interpret the rollback as the actual data shifting to an incorrect one, such as Jan. 6 1980. That could cause a host of issues because accurate timing information is critical to location data.
In other words, incorrect data could have major consequences beyond receivers just displaying the incorrect date.
Because of that, the DHS is recommending that people in charge of critical systems and infrastructure, along with business and private users who think that the GPS rollover could cause problems, should prepare for the event.
Not all GPS devices will be affected. Receivers that conform to IS-GPS-200 standards and provide UTC should be unaffected. These “fixes” for the issue can be delivered via software patch, but its availability depends on how old a device is and how reliable the manufacturer is.
While most modern devices made after 2010 should be unaffected, older and unpatched GPS devices will likely still be vulnerable to problems.
As such, the DHS has published a list of recommendations for anyone who may be impacted. You can read their report here.