The US GPS* protocol represents times using a 10-bit field for the week number. This has already rolled over once, from 1023 back to 0, back in 1999, which broke some devices that hadn’t been designed to cope with it. A second rollover is now approaching, as of April 6th (the first Saturday in April). Guess what’s going to happen this time ... <https://www.theregister.co.uk/2019/02/12/current_gps_epoch_ends/> *Seems the original official name “Navstar” has been dropped, and “GPS”, instead of being a generic term for such satellite-based navigation systems, is now the specific name of the US one.