In Ottawa we celebrate the first Monday in August, the Ontario Civic holiday, as Colonel By Day in honour of the man in charge of the construction of the Rideau Canal.
Although a normal work day on the Quebec side of the Ottawa River, and even in Ottawa many stores will be open, much of Ottawa will celebrate, notably in and around the Bytown Museum at the northern end of By's canal.
Admission is free The event has plenty going on for all ages and is supported by many local museums, heritage, historical and genealogical organizations who bring displays. It's also a good networking occasion. I expect to be there.
There's more information at http://www.choocopo.ca/english/cbday.html.