GPS uses 10 bits to store the week. That means it runs out... oh heck – April 6, 2019
Older satnavs and such devices won't be able to use America's Global Positioning System properly after April 6 unless they've been suitably updated or designed to handle a looming epoch rollover.
If devices in use today are not designed or patched to handle this latest rollover, they will revert to an earlier year after that 1,024th week in April, causing attempts to calculate position to potentially fail. System and navigation data could even be corrupted, we're warned.
So if you use an older GPS device that suddenly starts showing odd behaviour after this date it may be due to this issue.
|Fun fact: GPS uses 10 bits to store the week. That means it runs out... oh heck – April 6, 2019 • The Register