Rollover check

Maritime users of the global positioning system standard positioning service (GPS-SPS) were urged to check systems ahead of the week counter rollover on 6 April 2019. It was feared some outdated GPS receiver systems would cease to function properly – with potentially serious impacts on navigation. The rollover occurs because the GPS system transmits time to GPS receivers using a format of time and weeks as a 10-bit value, which started on 6 January 1980, and can only count 1,023 weeks.