A: The agreement is to be formally adopted Oct. 19, 90 days after it was endorsed by the U.N. Security Council. Oct. 19 is also the day Iran and the six world powers that concluded the accord — the United States, Germany, Britain, France, Russia and China — are to start taking steps to comply, although most of the early burden falls on Iran.
A: That does not happen until “implementation day.” Nobody knows when that may be. U.S. experts say it will take six to nine months for Iran to carry out the initial nuclear steps required for the accord to take effect. Iran insists it can act more quickly, in weeks or months.