Many of Colorado’s 63,000-some high school seniors start taking standardized science and social studies tests this week, an event that will mean time off for younger students in some districts.

This is the first year that seniors will have to take a portion of the state’s standardized tests, known as the CMAS. In the past, ninth and 10th graders took the language arts and math tests, 10th graders also took science tests, and juniors also took the ACT.

The expansion of testing at the high school level — 11th graders now have to take language arts and math exams — has been a sore point for many students and parents, and has become part of the debate over the state testing system.

One complaint is that testing disrupts classroom instruction, and that’s exactly what’s happening in at least three large districts – Boulder Valley, Cherry Creek and Douglas County.

Chalkbeat Colorado checked with eight major metro-area districts. Administrators in those three districts said schedules would change for some freshmen, sophomores, and juniors because of issues specific to certain high schools, such as numbers of computers and availability of computer labs and other rooms.

Here’s a rundown:

Boulder Valley – Some 5,700 ninth, 10th, and 11th grade students at Boulder, Broomfield, Fairview and Monarch high schools will get the mornings of Nov. 13 and 14 off so seniors can take their tests.

“In the four largest high schools we are unable to accommodate the online assessment when the other students are in attendance,” said Superintendent Bruce Messinger. “… Even with this assessment plan we will be transporting hundreds of laptop computers from other schools to the high schools so that every student has a device for the assessments. In order to administer the online assessments we need to have the students take the assessments in classrooms/tech labs so the students have wireless access.”

Cherry Creek – Spokeswoman Tustin Amole said, “Underclassmen will have two days off during the seniors’ tests. We are not able to run a normal schedule for them on the testing days due to space.” That affects some 12,000 ninth, 10th, and 11th graders on Nov. 13-14.

Douglas County – This south suburban district has a complicated schedule to accommodate the tests. Underclassman were scheduled for a half-day off Wednesday and Thursday at Chaparral, Castle View, Douglas County, and Rock Canyon high schools. There will be schedule changes Nov. 12 and 13 at Highland Ranch, Mountain Vista, and ThunderRidge high schools.

Other big districts will be juggling classes and tests with schedule changes.

Adams 12-Five Star – “We’re not having to make schedule adjustments to accommodate CMAS tests,” said communications chief Joe Ferdani.

Aurora – There will be no schedule changes or early release of students

Denver – Spokeswoman Kristy Armstrong said, “It has been stressed to schools that instructional time should be impacted as minimally as possible. And we’re not aware of any schools releasing early.” (Armstrong was asked about DPS plans last week. Since then East High School has announced underclassmen will have the mornings of Nov. 12 and 13 off.)

Jefferson County – “It is our understanding that some schools are making adjustments to their bell or period schedules, as needed, to enable testing to be completed, but school will be held for all students during the testing window,” said spokeswoman Lynn Setzer.

St. Vrain – There are no schedule changes because of testing.

The “testing window” for the senior CMAS tests opened on Wednesday and runs through much of November. Districts can choose when to give the tests.

Some elementary and middle school students took the tests last spring. Achievement levels were generally low (see story).