The Prime Meridian Conference established Greenwich, east of London, and the site of the observatory where Newton had done so much to establish the mathematics of planetary motion, as the point from which time would be measured. Though much of the rest of the world was initially resistant, and time was not centred on Greenwich by Europe and America until the International Conference on Time in Paris in 1912, the Prime Meridian Conference also divided the world into twenty-four zones separated by an hour's difference, and enshrined an exact moment at which the universal space-time day would begin.
Childs, Peter. "Prime Meridian Conference -Greenwich becomes the degree zero". The Literary Encyclopedia. First published 01 January 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=898, accessed 19 April 2014.]