But the talks on Wednesday are actually to take place one day after a date that had widely been reported as the framework deadline. Indeed, on Tuesday, the Washington Examiner described that day’s date, March 24, as the “original deadline” for such an agreement, suggesting that the negotiators had effectively extended the deadline by a week without acknowledging that they were doing so.

Of course, the original deadline not only for a framework agreement but for a final one was actually last summer. Following a lack of progress, this was extended to November 24 and then was extended again to the end of June with the understanding that a framework would be established in March. Now the Examiner points out that the supposed deadline for that preliminary accord has passed without any such agreement and without further progress by the US Congress toward legislation related to the issue.

Two bills are pending in Congress but have been delayed by Democrats who support the measures but have agreed to wait at least until the president completes negotiations over the framework deal. One bill would grant congressional oversight on any such deal and would require periodic demonstration of Iran’s compliance. Another would outline more punishing economic sanctions to be imposed on the country if a deal is not finalized or if Iran is found to cheat on it.

The lack of any further action on these bills on Tuesday suggests that Congress has embraced the later deadline, despite congressional statements on the talks specifically citing March 24. The Obama administration has been able to accomplish this silent extension and to get Congress to accept it by exploiting initial vagueness about the details of the November extension.

At that time, negotiators said that the final deadline was to be the last day of June and that a framework agreement would be due after four months. The March 24 deadline was determined by projecting forward exactly four months from the previous lapsed deadline, but March 31 can be justified by looking back three months from the final deadline. Negotiators on both sides have insisted that that is indeed the final deadline.

But in the meantime, vagueness regarding the framework may still be further exploited to evade public expectations after the now-definite March 31 deadline. At the same time that the exact deadline was not declared, neither was the exact content of any such preliminary agreement. Many have assumed that this would take the form of a written accord, but last week the US State Department explicitly denied rumors that a draft agreement was making the rounds at Lausanne.

On Tuesday, NPR’s Morning Edition discussed what might be presented to the public if progress is made in the talks this week. The program described the end of March as simply being a deadline to “get something done,” and clarified that while some are looking forward to a “framework agreement,” others have described the negotiators as merely working toward a “political understanding.”

The latter terminology has especially been championed by Tehran, in keeping with Supreme Leader Ayatollah Ali Khamenei’s public rejection of the very idea of splitting negotiations into two parts. The non-specific language may leave open the possibility for Iran to continue rejecting a formal framework at the same time that the US claims that a “political understanding” has been reached regarding what the two sides will be working toward in the next three months.