Why do calligraphy classes always have classes at night?

Details are as follows.

1, there are other courses or jobs during the day, and the time is relatively free at night, which is convenient for students to come to class.

2, the temperature is low at night, which is more suitable for practicing calligraphy, not easy to sweat, and feels better.

3. The environment is quiet at night, and there is no noisy sound interference, which is conducive to concentrated study.