Question

Why the canada has 6 different standard zones?

Answer 1

Because Canada is 2nd largest country in the world and it needs different zone to cover time of country it needs 6 different time zone.
biggest country is russia it has 11 different standard time zones.

Answer 2

Canada is 2nd largest country in the world.thus is extend from all directions.Canada covers more longitudes.1 longitude =4mins.Canada needs 6 standard zones

I know it's breif.but may be it helps you...