GPS geopositioning system was launched in 1978, with its internal clock has been designed only for 20 years. April 6, 2019 counter overflowed for the second time and the GPS time has gone to zero.
Time GPS is not a year and a month, only weeks meter (GPS week rollover), which allocated only 10 bits, respectively, the counter can be set to 0-1023. First reset the counter was August 21, 1999, the second is now.
Most devices that work with GPS, this is taken into account, and they understand that if the counter is zeroed out, come April 2019. But there is a big, big problem. If the device or rather its software released before 1999, it is confident that when the counter is reset, come August 1999, and not in April 2019. Sometimes the device with the software are installed in a new technology. So happened some airplanes Boeing 787s: their navigation systems have decided that it is 22 August 1999 and refused to fly planes. Now the owners of these planes are waiting for Boeing will release an update.
In 2039 most likely all repeat: there are devices, GPS time, which will jump from 2039 to April 2019.
All in all, it was necessary to "not greedy" and select 6 extra bits to counter this unfortunate weeks, but 20 years from now no one had not thought.
© 2019 Alex Nadozhin