126 days

Eighteen is a composite number, its proper divisors being 1, 2, 3, 6 and 9. Three of these divisors (3, 6 and 9) add up to 18, hence 18 is a semiperfect
number.

It is a heptagonal number, and as the sum of the first three pentagonal numbers, it is a pentagonal pyramidal number. It is also the sum of the totient function for the first seven integers.

The atomic number of argon.

The Hebrew word for "life" is חי (chai), which has a numerical value of 18. Consequently, the custom has arisen in Jewish circles to give donations and monetary gifts in multiples of 18 as an expression of blessing for long life.

In many parts of the world, 18 is the age minimum for for purchasing tobacco and alcoholic beverages. It is also the voting age in many countries. During the Vietnam War, Americans could be drafted at an age as low as 18, but were not allowed to vote in most states until they were 21. A movement spread to lower the voting age, and in 1971, the Twenty-sixth Amendment extended a guarantee of suffrage to anyone 18 years or older in all states. The voting age was lowered from 21 to 18 in the U.K. and many other nations around that time.

Eighteen is also the age in most countries at which a person may appear in pornographic video, if pornography is legal at all, or express legal consent to sexual relations with another.

In addition, eighteen year-olds in the United States have the right to bear arms, own property, marry without parental consent, get an abortion, donate their body to science, obtain a passport, and serve on a jury.

Bobby Labonte's car number in the NASCAR Winston Cup Series when he won the 2000 Championship. This is J. J. Yeley's car number as of 2006.

The number of holes in a stipulated round of golf.

DVD-18 is double-sided, double-layered DVD format.

The 18th Amendment - After one year from the ratification of this article the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States and all territory subject to the jurisdiction thereof for beverage purposes is hereby prohibited.
The Congress and the several States shall have concurrent power to enforce this article by appropriate legislation.
This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by the legislatures of the several States, as provided in the Constitution, within seven years from the date of the submission hereof to the States by the Congress.

18 weeks.

and no.
it's never going to stop.
to think it will is just asinine.