In Alberta DST was voted in, in a plebiscite, in 1971. BC passed it's bill in 1968.
At one time Calgary had the right to enact DST but Edmonton didn't.
http://www.epl.ca/infofile-detail?su...0and%20Alberta
I grew up before DST was enacted and I've never seen the purpose of it other than letting kids stay out later. The old rule was they had to be in when the street lights went on.