If you can extend it once, try try again...
http://www.channelnewsasia.com/stories/afp_world/view/72042/1/.html Voting extended for second time in Iran polls due to "high turnout":
TEHRAN : Polling stations across Iran have been ordered by the interior ministry to remain open for a second additional hour until 8:00 pm (1630 GMT), conservative-run state radio announced, saying the decision was taken because of a "high turnout".
Voting in the controversial parliamentary elections had been scheduled to end at 6:00 pm, but extensions are common in Iranian polls.
It was the second one-hour extension announced by the interior ministry, which can choose to prolong polling up until midnight.
Iran's clerical leaders have been calling for a high turnout in the polls, which are all but certain to see religious conservatives win control of the Majlis and deal a crushing blow to reformists and President Mohammad Khatami.
But turnout was the only real element of suspense, after reformers disqualified from standing urged the electorate to stay at home in protest.
That's not a new extension. That was reported here hours ago.
Polls were closed at 19:00 Local time. <<< Confirmed by Local TV and some other Persian websites.
open 'til midnight....surprised they didn't do that.
If they're going to make fools of themselves in front of the international media, might as well just have gone all the way.