Summer students gather in front of the Viscount Bennett Centre. (CBC)

A growing number of teenagers in Calgary are giving up their lazy days of summer to be hard at work in the classroom instead.

Summer school enrolment is up by 15 per cent from last year at Chinook Learning Services — the continuing and adult education division of the Calgary Board of Education — according to its prinicpal of summer school programs, John Fischer.

The increase is partly due to a change in how summer school is viewed by students — the old stigma it carried has faded, according to Fischer.

"So summer school is not looked upon as a penalty, but it's looked upon in that we're looking to meet the needs of individual students in many different ways," Fischer said.

There are about 4,000 high school students taking a wide range of condensed, four-week courses this July, from core subjects such as math and English to options such as phys ed and art.

"I don't mind because of our future it matters more than just, like, summer," said Diana Hussain, who graduated from high school last year — and was already accepted to university — but wants to upgrade her marks.

Aside from a $70 registration fee and book rentals, summer school is free for students in the public system.

With thousands of students prepared to spend July in school, the real challenge for Fischer is convincing enough teachers to give up part of their vacation too, he said.