Canadian prime meridian plaque
Plaque on rear of the Dominion Astrophysical Observatory building in Ottawa. 05h 02m 51.940s West of Greenwich. Prior to 1883, local mean time was used throughout North America, resulting in an inordinate number of local times. This caused convoluted regional and national train schedules. Sandford Fleming, a Canadian, proposed Standard Time at a Meeting of the Royal Canadian Institute on 1879 February 8. This was the first time the world was partitioned into time zones; which required significant knowledge of longitude and surveying, hence the importance of the prime meridian.