This sounds like a lot of time.
Students then engage in individual or group assignments for the other seventy-two hours.
Local study group meetings occur within one-two week time frames, at the convenience of just the teachers involved. Research tells us that people learn more if instruction is paced with learners given time for new ideas and practices to be analyzed and internalized. It takes time to learn, to try out ideas in one's class, and to understand and assess their impact on students' learning.