here in Quebec, (because in the rest of canada it's not the same apparently) it work like this
Kindergarden
you have to be 5 years old at september 30th to start. but the class start at the end of august. So, if you are born like me at the end of september (i'm born on september 27) you actually start at 4 and turn 5 after the class start. if you are born on october, you have to wait a whole year to start school. on of my friend is born on october 4th 1978, and i'm born on september 27th 1979, so we start school at the same time.
so when i turn 13, i was in secondary 2, he was in secondary 1
primary
1 - 2 - 3 - 4 - 5 - 6
secondary
1 - 2 - 3 - 4 - 5
then you have the higher education that goes
CEGEP pre university 1 - 2
University BAC 1 - 2 - 3
then 2 more year for a master and two more for a doc.
or
CEGEP Tech (we you actually study for a career in something. like a nurse, a computer tech, a social worker, dental hygienist, etc)
1 - 2 - 3
or
A professional school (usually more handy work, so hair styler, mecanic, appliance repair, plumber, etc... ). It also the only higher education level that doesnt require a secondary 5, you can start after secondary 4
1 - 2