From IRS: “Maintenance on the Modernized e-File (MeF) system originally scheduled for Saturday Sept. 19 is postponed until Saturday Sept. 26. IRS will be conducting system maintenance from 7:00 a.m. until 8:00 p.m. Eastern Time on that day. Please refrain from accessing the MeF Production and ATS Systems to transmit submissions, get acknowledgements, retrieve state submissions, send state acknowledgements or submit any other service requests.”

From Tax Court: “The Court will be undergoing system maintenance upgrades on Saturday, September 19, from 9 am to 5 pm Eastern time. During that time, there may be a brief interruption in service as systems are restarted. We apologize for any inconvenience.”