In education, as in most everything, the ultimate scarce resource is time.

What does it mean to spend time well in education? How much is school time worth? This lesson looks for the answers.

How much is an instructional hour of K-12 worth?

As discussed in Lesson 4.3, there are roughly 1,000 instructional hours in an American school year. Given that, what’s the rough per-student cost of an instructional hour? Simple: it's the cost per year divided by a thousand.

Over time, the dollar cost of education has risen with inflation, a subject we discussed in some length in the context of teacher pay pay. As of California's state budget for 2023-24, the average annual cost per student in California public K-12 education was about $18,000 per student.

Rule of thumb: Students' time is more valuable than minimum wage

…which comes to about eighteen bucks an hour.

This rule of thumb can be handy for evaluating the rough dollar value of things that take time or save time in California schools. What is the instructional time cost of a one-hour bus delay that affects 50 students? How much instructional time cost could be recovered through smoother transitions between classes? How can we think about the instructional time cost of administering a standardized test, or of taking kids on a field trip? Putting a dollar value on instructional time per student doesn’t make tradeoffs simple, but it can help make them more concrete.

Spending time well: Time management skills can be learned

The clock spins in only one direction. Each day, teachers have limited time to inspire and guide students through their lesson plans. Some teachers make masterful use of their limited minutes with students, elevating the use of time to an art form. In Teach Like a Champion and his other work, Doug Lemov describes techniques collected from master teachers that enable them to keep students engaged and learning, with practice. His instructional videos have become popular because they are practical. His primary thesis is that teaching skills can be learned and improved, with clear examples.

In the Ed100 blog
How California changed school start times

Time in school has a rhythm to it. Classes begin and end at particular, scheduled times, marked by bells, buzzers or chimes. But do they have to be? In the past, clocks were rarely synchronized, but nowadays there is no longer any real doubt about the correct time. Factories and businesses have mostly done away with clocks that make noise, and some schools are getting rid of bells too, as EdSource reports.

What is block scheduling?

In the Ed100 blog
Using School Time Creatively

Traditionally, school days are simply chopped into class periods of equal length, but they don't have to be. For example, some schools use block scheduling to create a mix of longer and shorter instructional segments that differ from one day to the next. Long blocks of double the usual length reduce transition time between classes. They also enable teachers and students to delve deeper into discussions, problem sets, art projects and lab work. There are different types of block scheduling, each with its own set of benefits.

Some schools create overlapping class periods, with some students and teachers starting earlier and others ending later, in order to create flexibility and address space issues.

Research about the impact of sleep on learning led to changes in California laws in 2019: High schools must not begin the school day before 8:30 a.m. Middle schools must not begin before 8:00 a.m.

Changing something as fundamental as the use of time in school affects everyone involved; it can be transformative, but it is also easy to make mistakes. There is some evidence that longer class periods may be beneficial, but there are many approaches and no easy answers about what works best. The National Education Association (NEA) urges school leaders to plan carefully and talk it all through with teachers before jumping to a new schedule system.

Time to prepare.

To do anything well requires preparation, which takes time. In the context of school, teachers need to know their material and have a solid plan to teach it. In many countries, school systems set aside time [PDF] in the school day and the school calendar for teachers to collaborate and prepare (learn more in Chapter 3, Teachers). The Learning Policy Institute provides a good overview of how to use time effectively in professional development.

Updated in December 2023