The FAA's nationwide ground stop advisory runs to 11.30pm ET, which is 4.30am UK time on Saturday, with 11pm ET (4am UK time) given as the estimated end time rather than the point at which the order lapses.
News9 reports that the FAA command centre advisory gives an estimated end time of 10pm Central (11pm ET) and an effective period running to 10.30pm Central (11.30pm ET). Yahoo News gives the effective period as 3.54pm ET to 11.30pm ET on 13 November.
Neither time is a promise that flights will restart. Yahoo News says the listed expiry does not guarantee flights will resume, and that the FAA has given no estimate for when normal operations will return. The advisory itself says departing traffic is to remain ground stopped until further notice.
The wording of the order, as quoted by News9, is unchanged:
"Due to extraordinary circumstances and for reasons of safety, all airports are ground stopped."
The FAA has still given no reason for the stop beyond those words.