Old GPS devices could become unusable and some tracking systems may fail after 6 April 2019:
https://www.gizmodo.com.au/2019/03/the-y2k-moment-for-gps-systems-is-just-a-month-away/
https://www.gizmodo.com.au/2019/03/the-y2k-moment-for-gps-systems-is-just-a-month-away/