This discussion reminded me about the GPS week number rollover problem. https://en.wikipedia.org/wiki/GPS_week_number_rollover I have an old Magellan GPS 2000 handheld receiver that suffers from this. Other handheld and portable automotive units I've owned have required firmware updates to address it. Coincidentally but unrelated, the next occurence will be in 2038, the same year (but a different month and day) as the Unix issue. -- Scott