The United Nations General Assembly (UNGA) meets annually in a regular session. The regular session begins on the third Tuesday of September each year and runs intensively from September to December, then resumes in January until all issues on the agenda are addressed, which is often just before the start of the next session. In addition to the regular sessions, the General Assembly may also meet in special sessions or emergency special sessions as needed.

The main period of intense work occurs from the opening in September until the Christmas break in December, including the general debate where world leaders typically address the assembly. The session then resumes after the break for more thematic debates and working group meetings until all business is concluded.

In summary, the UN General Assembly meets once a year in a session that spans most of the year, with the most important activities happening in the fall months and continuing into the next year until completion.