US and Iran sign an agreement by...?

This market will resolve to “Yes” if the United States signs any written agreement with the Islamic Republic of Iran by the listed date, 11:59 PM ET. Otherwise, this market will resolve to “No”. A qualifying agreement must be signed by both an authorized representative of the United States and an authorized representative of the Islamic Republic of Iran. Both parties must either sign the same document, or sign individual documents which substantively and directly indicate acceptance of the same underlying agreement, regardless of minor or translated differences between the signed versions. Both physical signatures and officially issued electronic signatures will qualify as signing. The primary resolution source for this market will be official information from the governments of the United States and Iran; however, a consensus of credible reporting may also be used.