TSP Name: Northern Natural Gas Company TSP: 784158214 Notice ID: 033918 Notice Type: Computer System Status Subject: SCHEDULED SYSTEM APPLICATION MAINTENANCE Critical: N Post Date/Time: 05/09/2016 03:10 PM Notice Status: Initiate For Gas Day(s): 05/09/2016 - 12/30/2999 Notice Effective Date/Time: 05/09/2016 03:00 PM Notice End Date/Time: 12/31/2999 08:59 AM Required Response Indicator Description: 5-No response required Notice Text: Beginning June 1, 2016, Northern will adjust the scheduled time of its nightly system application maintenance window to occur from 11 p.m. to 3:30 a.m. The current window is 10:30 p.m. through 3 a.m. The 30 minute change is being implemented to accommodate customers' review of Intraday 3 scheduled quantities, which are required to be available by 10 p.m. During normal system application maintenance, all of Northern's business applications will be unavailable. EDI transactions will be processed after the application systems return to normal operations at 3:30 a.m. All times are Central Clock Time (CCT). If you have any questions, please contact your customer service or marketing representative.