It's State of the Union time. (AP Photo)

UPDATE: Looking for the latest? The speech has ended. Our live updates are here, and a look at Obama's remarks here. Read a full transcript of his remarks.

This post has been updated and corrected.

It's time for the State of the Union, the annual speech where the president proclaims that the state of the union is (fill in the blank) and outlines his legislative priorities.

President Obama has been playing spoiler to his speech, announcing a slate of actions and legislation he will outline in his address. So what is this speech, when will it happen and why will it take place? Let's fill you in on some State of the Union basics, including what we expect him to say.

The Post's Ed O'Keefe details the pomp and circumstance of the most-watched political event of the year: the annual State of the Union address. (Theresa Poulson/The Washington Post)

 1. What time is the State of the Union?

It starts at 9 p.m. Eastern time on Tuesday, Jan. 20. Get your popcorn ready, because it starts on time.

2. Where can I watch it?

It is typically carried live by all major networks and cable news channels, so it's pretty hard to miss. Emily Yahr breaks down who's covering and how -- and what shows you won't get to see tonight.

3. Where does it take place?

President Obama will deliver the speech from the floor of the the House of Representatives.

4. Who will be there?

The president stands at a podium in front of Vice President Joe Biden and House Speaker John Boehner. Members of Congress, the Supreme Court and almost all of the president's Cabinet will be in attendance. Each year someone, typically a Cabinet member, does not attend. This person is known as the designated survivor (this year it's Transportation Secretary Anthony Foxx) and would become president should something catastrophic happen at the speech. The White House also invites special guests to sit in a box with First Lady Michelle Obama.

5. What will the president say? 

Typically the topics that the president will address are a closely guarded secret. Not this year. Spoiler alert: The White House has already unveiled a lot of the programs Obama will call for in the speech, from new taxes on the wealthiest individuals, making community college free, faster Internet service, paid sick leave, cybersecurity and more in the days and weeks before the address.

6. Will there be breaking news? 

There may be some proposals that we don't yet know about, but don't expect anything crazy (see above).

7. How long is the speech?

The speech typically lasts about an hour. The longest ever? Bill Clinton in 2000, when he spoke for 1 hour, 28 minutes and 49 seconds, according to the Presidency Project at the University of California-Santa Barbara. The shortest? Richard Nixon in 1972, at 28 minutes and 55 seconds.

8. Why does the State of the Union take place?

Something called the Constitution. According to Article 2, Section 3, the president "shall from time to time give to the Congress information of the state of the union, and recommend to their consideration such measures as he shall judge necessary and expedient." (Some question whether it's still necessary.)

9. How many State of the Union addresses have been given?

Well ... that depends. Every president since George Washington has delivered a message to Congress each year. It used to be written. Modern presidents have given it as a speech. It has been known formally as the State of the Union address since 1947. The past five presidents have addressed Congress shortly after being inaugurated; because they were in office for such a short amount of time it's technically not called a State of the Union address.