[3] A July 2010 Time magazine article has a chart showing that students in the United States have the highest total yearly instructional hours of those nations listed.
[1] Various studies have yielded widely different results in regard to the correlation between school time and academic achievement.
Research suggests that expanding instructional time is as effective as other commonly discussed educational interventions intended to boost learning, such as increasing teacher quality and reducing class size.
[5] Other researchers conclude that more time spent in the classroom will have little impact on academic achievement if it is not accompanied by other education reforms.
They show that the key to student learning gains is the quality of the teacher, not the amount of time spent in school.