The United Nations General Assembly’s regular session officially lasts one year, from September to the following September, but the intensive part most people mean runs only a few months.

Quick Scoop

  • The General Assembly opens every year on the third Tuesday in September and formally runs until the next September as a “session.”
  • In practice, the main working period is from September to about December, when the general debate and most committee work take place.
  • After December, the Assembly can reconvene as needed from January up to the start of the next session, so the same session can have “resumed” meetings later in the year.
  • For people in New York wondering about traffic and VIPs, the really disruptive “High‑Level Week” (when world leaders give speeches) usually lasts about 9 working days right after the opening.
  • Some local city notices describe this high‑impact part as roughly “two weeks in September” each year because of security and street closures.

What “how long” can mean

When people ask “how long is the UN General Assembly,” they usually mean one of three things:

  1. Length of the full session
    • Legally and procedurally, one regular session = about one year, from mid‑September to the next mid‑September.
  1. Length of the main active period
    • The main part runs from opening day until the December holiday break, when most resolutions and debates happen.
  1. Length of the high‑level week
    • The general debate, when presidents and prime ministers speak, is held over nine working days, typically starting the week after the opening.

So, if you’re asking in everyday terms:

  • “How long is the UN General Assembly session?” → About one year.
  • “How long does the busy part last?” → Roughly September to December.
  • “How long is the really intense world‑leaders week?” → Around nine working days, often described as about two weeks of disruption in New York.

Bottom line: Officially a year‑long session, but the heavy political and media action is concentrated into a few weeks in September and a few months through December.

Information gathered from public forums or data available on the internet and portrayed here.