Midnight Monday was the latest in a series of deadlines in the Iran nuclear negotiations. Here are key dates in the past few months of talks.
March 9, 2015
Forty seven Republican senators release a letter to Iranian leaders, saying any nuclear deal would require congressional approval.
Parties to the negotiations miss the self-imposed midnight March 31 deadline.
Iran and the major powers -- the United States, Britain, China, France, Germany and Russia -- agree to "key parameters" for a preliminary deal.
The White House relents when Congressional members demand lawmakers have a voice in the nuclear talks.
Iran and the major powers agree to give themselves until July 7 to reach a final deal.
Talks are once again extended, through July 10.
Negotiators missed U.S. congressional deadline, meaning the Republican-led U.S. Congress will now have 60 days, rather than 30, to review a deal. Iran and world powers extend talks again, to July 13.
Diplomats hint the two sides are close to having the complex document ready.
Iranian and Western diplomats say negotiators have reached a deal.