Leap Second Means ATSC PSIP Settings Must Be Changed

By Doug Lung
published

You might not have noticed, but the earth gained a second at midnight UTC on June 30. A leap second, 23:59:60, was added between 23:59:59 and 0:0:0 UTC. As the Wired article ‘Leap Second’ Bug Wreaks Havoc Across Web, pointed out, the extra second caused some problems for web sites. 

For broadcasters, the leap second means that the GPS_UTC_Offset field of the PSIP System Time Table (SST) is now 16 seconds, not 15 seconds. Check your PSIP SST using a program like TSReader to make sure the correct offset and the correct UTC time is being sent. 

NAB's TV TechCheck for May 14 has details on the GPS offset change as well as the other June 30 deadline – EAS CAP compliance.

Doug Lung
Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack.
A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.