The summer vacation in American universities generally lasts for three months, from June to September, and the winter vacation is shorter, including legal holidays such as Christmas and New Year, which lasts for three weeks to one month. Spring break is in March and lasts for a month.

American universities have different types of semesters, including semesters, semesters, semesters and early semesters.

Among them, the semester system is the most, generally. The first semester begins at the end of August, and there is usually a freshman orientation week, which ends in the middle and late June of that year. The second semester begins in early January and ends in late May.

However, the academic year system divides a year's curriculum into four seasons, namely, spring, summer, autumn and winter. One semester per season ($ term) lasts only two and a half months (ten to twelve weeks, and about eight to ten weeks in summer), so the curriculum is very tight.

The three-semester system divides the school year of 12 months into three equal parts, lasting 16 weeks. The first semester (autumn class) starts in late August or early September and ends before Christmas (1February 25th). The second semester (winter class) starts from the beginning or middle of 1 month and ends in April. The third semester begins in late April or early May and ends in August. The third semester is divided into two semesters, namely, spring class (April to June) and summer class (June to August).

The early semester system divides a school year (nine months) into two units, each with 15 to 18 weeks. The first semester (autumn class) is slightly shorter than the second semester (spring class). The first semester begins at the end of August and ends around1February 20th. The second semester begins in mid-January and ends in mid-May.