What was going on when I was born?

Every other Thursday at City Hall, a Cornell-trained economist from upstate who looks younger than his 28 years sits in a tall leather chair that is capped by a carved eagle. At that moment, in that place, the economist, John J. Gilbert 3d, is the Mayor of the City of New York. This is Board of Estimate day, an almost seamless stretch of public hearings, votes and horse-trading that can spill over into the next morning. It features a cast of characters very different from the nameplates around the U-shaped dais. The eight elected officials who make up the board are rarely seen. Instead, they send deputies, assistants and other aides.

An article in Business Day June 4 about utility name changes misidentified the main subsidiary of the Florida Progress Corporation. It is the Florida Power Corporation.

An obituary last Saturday, of a former writer for Better Homes and Gardens and The Ladies' Home Journal, misidentified her. She was Gladys Denny Shultz.

CBS Inc., which two years ago raced to be one of the first communications companies authorized to build a satellite-to-home television system, yesterday abandoned the project, citing ''some open questions and the risks involved.'' In a terse statement, the company said it would not meet a Federal Communications Commission deadline to begin construction on the project by next month, meaning CBS will be forced to surrender its building permit. Analysts said the move, which came as a surprise, aroused doubts about the future of the direct broadcast satellite industry, in which television programs would be beamed straight from orbital satellites to small antennas on rooftops. More immediately, it appeared to jeopardize the future of the Satellite Television Corporation, a subsidiary of the Communications Satellite Corporation. Comsat had been negotiating with CBS since December on a joint venture in the new field. Both Comsat and CBS officials, however, had made it clear recently that they would not go ahead unless they found a third partner to share the costs.

Leftist guerrillas overran El Salvador's largest hydroelectric dam today in their most important military operation in the last six months. Government forces were reported to have retaken the dam later in the day. During an eight-hour battle with Government forces that started at 2 A.M., the rebels destroyed the 135- megawatt Cerron Grande dam's electrical generating substation but did not destroy the plant's central computerized control room. The dam is 25 miles northeast of San Salvador in the heart of a heavily contested guerrilla zone and has long been considered a prime target for rebel attack. The assault today was the biggest rebel operation since the guerrillas destroyed the army's base at nearby El Paraiso last December and the Cuscatlan bridge, one of the country's largest, at the beginning of the year.

Secretary of State George P. Shultz said today that Fidel Castro's decision to release 48 American and Cuban prisoners to the Rev. Jesse Jackson was intended as a ''propaganda victory.'' He said the Cuban leader had not given any sign he was ready to moderate Cuba's ''subversive'' policies in Latin America. In an interview with Washington correspondents of The New York Times, Mr. Shultz stuck firmly with the Administration's tough policy toward both the Cubans and the Nicaraguans. He said that despite Congress's refusal to provide more money for the anti-Sandinista rebels, or contras, in Nicaragua, he believed the insurgents would ''continue in one way or another'' and that the Administration would provide ''moral support'' for rebel efforts to secure funds elsewhere.

The Rev. Jesse Jackson today disavowed as ''reprehensible'' the words of Louis Farrakhan, a Black Muslim supporter who had described the creation of Israel as an ''outlaw act'' and called the nations that helped found and now support Israel ''criminals in the sight of Almighty God.'' In a statement issued through his campaign office here, the black Democratic Presidential contender said: ''I find such statements or comments to be reprehensible and morally indefensible. ''I am a Judeo-Christian and the roots of my faith run deep in the Judeo- Christian tradition. Such statements and thoughts have no place in my own thinking or in this campaign.''

YACHTS, fishing boats, lifeboats and all other manner of seagoing vessels will be the focus of attention this weekend - with a few runners thrown in for good measure - at Harbor Festival '84. The eighth annual festival, as well as other historical, patriotic and artistic events, will start the metropolitan area's celebration of Independence Day, which does not arrive until next Wednesday. The weekend's highlight is the Liberty Cup, the first world-class yacht races in New York Harbor in more than 60 years. The series of head-to- head match races, which will feature the yachtsmen Gary Jobson and Ted Turner from the United States, and six competitors from other countries, begin tomorrow and continue through Tuesday. Races tomorrow and Monday will pit the United States against Australia, the competition that decided last year's America's Cup, which was won by Australia II. The races, to be sailed in the Lower Bay and Raritan Bay to the south of Great Kills Harbor, will run from 10 A.M. to 6 P.M. each day. The pairs of huge spinnakers puffed out in the wind, can best be seen from the starting gate, at the Richmond County Yacht Club on Staten Island or from the water. The telephone number for a race schedule and information about other festival events is 759-7570.

''I find such statements or comments to be reprehensible and morally indefensible.

The Motorola Corporation yesterday introduced a powerful new microprocessor that analysts said would make it possible for the next generation of desktop computers to rival the power of giant mainframe machines. The new chip is the long-anticipated successor to the Motorola 68000, the microprocessor that lies at the heart of Apple Computer Inc.'s Macintosh computer, among others. But the new device, called the 68020, can manipulate 32 bits of information at a time. It can also exchange data with outside devices at that pace, twice the rate of the older chip. A bit is the most basic unit of data handled by a computer.

A House- Senate conference committee today approved a major overhaul of the Federal bankruptcy system that has required two years of struggle. In a victory for labor unions on an issue they had declared their top lobbying priority of the year, the conferees agreed to limit employers' freedom to escape union contracts by declaring bankruptcy. That agreement, reached early this morning in a marathon bargaining session, removed the last major impediment to passage of the bankruptcy bill. The bill was originally intended to reorganize the bankruptcy courts in compliance with a Supreme Court ruling issued two years ago today.

The Economy A major overhaul of the Federal bankruptcy system was agreed to by House and Senate conferees. They removed the last major impediment by agreeing to limit employers' freedom to escape union contracts by declaring bankruptcy. The overhaul would also limit individuals' ability to avoid paying debts by declaring bankruptcy. And it would remove bankruptcy judges' authority over nonbankruptcy issues, which the Supreme Court said must be the province of judges with lifetime tenure. (Page A1.) The nation's trade deficit narrowed to $8.84 billion in May from a record $12.2 billion in April as the nation used less imported oil, the Government reported. But officials said they did not expect further declines in the deficit anytime soon. (D10.)