The original transition date was slated for Feb. 17. Congress voted to delay the transition out of concern that too many households were not prepared for the change.
Viewers who use an antenna to receive free, over-the-air TV signals must have a digital-ready TV set or a DTV converter box attached to an existing non-digital set. The federal government is offering consumers $40 coupons to offset the cost of converter boxes, most of which retail between $50 and $80.
Stations in Birmingham have been broadcasting on temporary digital channels for months, but they'll be moving to their permanent DTV channel numbers when the analog signals are turned off. For that reason, all DTV viewers will need to run the "channel scan" feature on their converter boxes or televisions Saturday.
People who subscribe to cable or satellite TV service will be unaffected by the transition.
Federal Communications Commission spokeswoman Edie Herman said about 3 million homes are still not ready for the switch, so they're offering additional help: They've enlisted volunteer groups across the country to provide free converter box installation for anyone who needs it.
Sharon Tinsley, president of the Alabama Broadcasters Association, said there are seven organizations in Alabama that are installing the converter boxes. She said that viewers can dial 211 anywhere in the state for information on how to schedule a converter box installation or contact local TV stations.
Herman said that the FCC is also staffing a DTV call center around the clock through Monday. They can be contacted by calling 1-888-CALL-FCC.
Information is also available on the Web at www.dtv.gov.
Congress in 1996 mandated the change from analog to digital television. Because digital signals are more efficient than the analog TV broadcasts that have been on the air for six decades, the transition will make room in the airwaves for wireless Internet and emergency communications services. Many viewers of DTV should also notice an improvement in picture and sound quality.
Peter Svensson of the Associated Press contributed to this report.