Thanksgiving has been an official holiday in Canada since 1879. With the exception of the Atlantic provinces (where it is an optional holiday), we will all be enjoying an extra day off on the coming Thanksgiving weekend.
The first North American Thanksgiving can be traced back to 1578, when the English explorer Martin Frobisher organized a day of thanks in Newfoundland to honour the reunion with his scattered fleet and crew members after enduring bitter winter storms near Baffin Island in the Eastern Arctic (now Nunavut).
In 1750s, the Pilgrim’s harvest celebration in Plymouth, Massachusetts, was brought to Nova Scotia. Halifax commemorated the end of the Seven Years’ War with a day of Thanksgiving in 1763, and the American settlers’ tradition of eating turkey and pumpkin pie was spread through Canada.
In the course of the following centuries, Thanksgiving was celebrated on different dates for different reasons by parliamentary proclamations. In addition to the most common “Blessings of an abundant harvest”, “For God’s mercies”, “To continue God’s mercies” and “For general thanksgiving to Almighty God for the blessings with which the people of Canada have been favoured”:
In 1921, Member of Parliament Herbert Macdonald Mowat of Ontario brought before the House of Commons a proposal for a single long weekend for Armistice Day and Thanksgiving Day. An amendment to the Armistice Day Act in May 1921 established that Armistice Day and Thanksgiving would both be celebrated on the Monday of the week in which November 11 occurred. Combining a day of festivities to celebrate bountiful harvest and a day of solemn introspection to remember those who sacrificed for the country met with strong disapproval from the veterans and the public at large. Nevertheless, Armistice Day and Thanksgiving remained on the same day for another 10 years. In 1931, MP Allan Neill introduced a bill to hold Armistice Day (which was to be renamed Remembrance Day) on November 11, and Thanksgiving was celebrated on October 12 that year. On January 31, 1957, Parliament finally proclaimed and set the annual observance of Thanksgiving on the 2nd Monday in October to separate Thanksgiving from Armistice Day and to bring the harvest celebrations earlier to reflect the shorter growing season in Canada.
Canadian Heritage, Government of Canada (http://www.pch.gc.ca/pgm/ceem-cced/jfa-ha/graces-eng.cfm)
Wikipedia: Thanksgiving (Canada) (http://en.wikipedia.org/wiki/Thanksgiving_(Canada))