In the second segment of our back-to-school series, 24 hours looks at how extended hours in Surrey schools has parents concerned. Read in our paper each Tuesday for the next four weeks.

Extended school hours implemented at another two Surrey schools this year have parents and students concerned, but the school district maintains the extra class time is necessary to keep the city's overcrowded schools under control.

Surrey North Secondary and Sullivan Heights Secondary now have an "extra block" attached to each school day, staggering the number of students attending class at any one time, and effectively extending days by about an hour.

It also increases capacity by 10%.

Almost immediately, several students expressed their frustration through social media.

"Who makes school start at 7:50 ... Apparently north surrey does," wrote one student on Twitter.

Another said, "North Surrey Students have to go to school an hour early now?!"

The concept met fierce opposition last year from students, who walked out in protest more than once, when it was introduced at the burgeoning Earl Marriott and Lord Tweedsmuir secondary schools.

But the school district doesn't anticipate any walkouts this time, said spokesman Doug Strachan.

"There were fears and concerns of how it would work, certainly, but overall the feedback was quite good from staff and students, parents particularly."

Strachan said the longer hours are required to meet enrollment demand despite the ongoing construction of two elementary schools and additions to two high schools announced for the city just last month.

Twelve additional portable classrooms, with space for about 300 students, are also anticipated this year.

Diane Vasvary, parent of a Sullivan Heights Grade 11 student, said she's already heard complaints from her son and his friends.

Older students, she said, are now asked to go home during extra "in-between" blocks and return later because of the lack of space in hallways "teeming with masses" of students.

Many parents also face challenges to pick-up and drop-off their teens for school due to the schedule shake up.

"Parents who have elementary as well as high school kids are all over the clock," Vasvary said.

"After-school sports is a big problem. Or other things like music classes, and the kids that work part time. It's going to be very challenging."

Surrey School District expects it would have up to 267 classroom portables this year, enough capacity for about 6,675 students at any one time.

The district is also seeking to acquire four sites for additional schools, but a timeline hasn't been made public.