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The Register: Fun fact: GPS uses 10 bits to store the week. That means it runs out... oh heck – April 6, 2019

tl;dr: GPS uses a 10-bit number to track the week, which is necessary to understand the signal from the satellites. It's about to rollover again (the last time this happened was in 1999), so patch your GPS or have an expensive paperweight.

Fortunately, according to the article, the standards changed almost 10 years ago to account for this, so if your GPS does spaz out in two months, you've either got something very old, or by a manufacturer who didn't think they needed to update their product to the new standard for nearly a decade...