It soon may be time to retire the phrase “fall television season.”

NBC Universal took a big step toward undoing one of the television industry’s oldest traditions by announcing Tuesday that it would move to a year-round schedule of staggered program introductions. The move is intended to appeal to advertisers, who crave fresh content to keep viewers tuned in.

And if it succeeds  and leads other broadcast networks to shift from their focus on a mass introduction of new shows  it could alter an American cultural cycle that extends all the way back to the days of radio, when families gathered around the Philco every September, as the school year began, to sample the new entertainment choices.

NBC plans to announce a 52-week schedule in April, a month before ABC and CBS will unveil their fall lineups at splashy presentations known as upfronts. The decision means that NBC will be committing to a new lineup of shows earlier than any of its competitors, while also inviting advertisers to build marketing plans around specific shows and perhaps to integrate brands and products into the plots of the shows themselves.

“We absolutely think this is going to change the industry,” said Michael Pilot, the head of sales for NBC. That was one of the goals cited by Jeff Zucker, the president and chief executive of NBC Universal, in comments he has made recently about how the strike by Hollywood writers could create opportunities to change some of the ways networks do business.