The phrase "outside class hours" is correct and can be used in written English.
You can use it to refer to times outside of the usual class time for a specific course or class. For example, "My professor has been holding office hours outside class hours to help students with their assignments."
Using the iPad given to every student, the workshop happened outside class hours.
At Garfield I tried out faithfully for skits and playlets that were done outside class hours under the coaching of a teacher.
The questionnaire was self administered by the students inside the classroom, but outside class hours.
Findings, ideas, and proposals are discussed in class and in meetings outside class hours.
During the whole course, the students organize plenary meetings outside class hours to discuss the progress they make.
Each team will be assigned "coaches" to assist them outside of class hours with their assignments.
She has also appreciated her professors' openness to share their expertise in meaningful conversations outside of class hours.
He attended high school at Phillips Exeter Academy, and later recalled that "the excellent science department even permitted certain students the unsupervised run of the laboratories outside of class hours.
Often outreach takes place outside regular class hours, and most outreach facilitators are scientists.
If students are assured of access to the lecture presentations outside of class hours (via the e-learning website), they would give their full attention to the lecturer and refer to the presentation later.
This category referred to journeys, as " having to get to three different places within a period of five hours" (TRS, female, 53 years), and access problems, such as the " difficulty of accessing the workplace for research purposes outside of class hours" (TRS, female, 36 years).
