In the school curriculum, one week and two weeks are used to indicate different teaching plans or curriculum arrangements.

For example, in a high school, there are four Fridays every month for school activities. In order to ensure that all classes can participate in these activities without affecting the normal teaching progress, senior high schools designate the first Friday of each month as "one week" and the second Friday as "two weeks". In this way, in the case of "single" and "double", they take turns to participate in the whole school activities, which can avoid causing too much interference to normal teaching.