GPS Week Rollover occurs on April 6, 2019, which could cause a mini "millennium bug" for some GPS devices. While this is a known issue arising from the way the system works, critical infrastructure operators whose systems use GPS are encouraged to prepare for the event. Most modern GPS receivers shouldn't be affected by this (devices that conform to IS-GPS-200 and provides UTC will be fine), but testing carried out by the U.S. Department for Homeland Security showed that there is a possibility that some will interpret the rollover date as January 6, 1980, or possibly some other incorrect date. This is where the headaches begin. Not only will the GPS receiver start reporting the incorrect date, but since accurate timings is critical to precise location data (an error of only a nanosecond in GPS time can equate to one foot of position error), an incorrect interpretation of this rollover can have big consequences. Read the article at ZDNet.