what time zone is ontario toronto?
North American Eastern Time Zone
neutral
 As of 1943 , Toronto was divided into 14 zones , numbered from 1 to 15 , except that 7 and 11 were unused , and there was a 2B zone . 

neutral
 The most important economic activity in Ontario is manufacturing , and the Toronto – Hamilton region is the most highly industrialized section of the country . The area from Oshawa , Ontario around the west end of Lake Ontario to Niagara Falls , with Hamilton at its centre , is known as the Golden Horseshoe and had a population of approximately 8 @.@ 1 million people in 2006 . The phrase was first used by Westinghouse President Herbert H. Rogge in a speech to the Hamilton Chamber of Commerce , on January 12 , 1954 . " Hamilton in 50 years will be the forward cleat in a golden horseshoe of industrial development from Oshawa to the Niagara River ... 150 miles long and 50 miles ( 80 km ) wide ... It will run from Niagara Falls on the south to about Oshawa on the north and take in numerous cities and towns already there , including Hamilton and Toronto . " 

entailment
 Among its other uses , in 1880 , measurements from the site were used as part of the effort to develop standard time . The observatory remained the official timekeeper for Canada until 1905 , when that responsibility was transferred to Ottawa 's Dominion Observatory . At exactly 11 : 55 am the clocks in Toronto fire halls were rung by an electrical signal from the Observatory . 

neutral
 Since the closing , the Ontario Science Centre has taken over the McLaughlin Planetarium 's role as Toronto 's public planetarium , though using a much smaller facility . 

contradiction
 Toronto 's renumbering took effect 1 May 1969 , accompanied by an advertising campaign under the slogan " Your number is up " . However , with impending plans for a national postal code system , Postmaster General Eric Kierans announced that the Post Office would begin cancelling the new three @-@ digit city zone system . Companies changed their mail addressing at their own expense , only to find the new zoning would prove to be short @-@ lived . 
